IVY Tech PHYS 101 Final Exam Summer 2018

Salt water has greater density than fresh water. A boat floats in both fresh water and in salt water. Where is the buoyant force greater on the boat? in salt water in fresh water The buoyant force is the same in both cases.

The buoyant force is the same in both cases.

A copper sphere that is 10 cm in diameter at an atmospheric pressure of 1.01 × 105 N/m2 is put into a chamber where the pressure is 1.0 × 106 N/m2. What is the change in the diameter of the sphere caused by this change in pressure? The bulk modulus for copper is 1.4 × 1011 Pa. -2.1 × 10-4 cm -2.1 × 10-5 cm -7.1 × 10-4 cm -7.1 × 10-5 cm -7.1 × 10-6 cm

-2.1 × 10-5 cm

At what, if any, temperature are the numerical readings on the Fahrenheit and Celsius scales the same? -30° -40° -50° -60° They can never read the same because they are based on different zeroes.

-40°

A 35-N bucket of water is lifted vertically 3.0 m and then returned to its original position. How much work did gravity do on the bucket during this process? 180 J 90 J 45 J 0 J 900 J

0 J

A uniform solid cylinder with a radius of 10 cm and a mass of 3.0 kg is rotating about its center with an angular speed of 33.4 rpm. What is its kinetic energy? 0.18 J 0.092 J 0.96 J 1.1 J 17 J

0.092 J

The coefficient of linear expansion of aluminum is 24 × 10-6 K-1 and the coefficient of volume expansion of olive oil is 0.68 × 10-3 K-1. A novice cook, in preparation of some pesto, fills a 1.00-L aluminum pot to the brim and heats the oil and the pot from an initial temperature of 15°C to 190°C. To his consternation some olive oil spills over the top. How much? 0.11 L 0.12 L 0.13 L 0.14 L 0.15 L

0.11 L

A 40.0-kg child running at 3.00 m/s suddenly jumps onto a stationary playground merry-go-round at a distance 1.50 m from the axis of rotation of the merry-go-round. The child is traveling tangential to the edge of the merry-go-round just before jumping on. The moment of inertia about its axis of rotation is 600 kg m2 and very little friction at its rotation axis. What is the angular speed of the merry-go-round just after the child has jumped onto it? 0.788 rad/s 0.261 rad/s 6.28 rev/s 2.00 rad/s 3.14 rev/s

0.261 rad/s

Two ice skaters suddenly push off against one another starting from a stationary position. The 45-kg skater acquires a speed of 0.375 m/s relative to the ice. What speed does the 60-kg skater acquire relative to the ice? 0.50 m/s 0.28 m/s 0.38 m/s 0.75 m/s 0.00 m/s

0.28 m/s

A 1.0-kg object moving in a certain direction has a kinetic energy of 2.0 J. It hits a wall and comes back with half its original speed. What is the kinetic energy of this object at this point? 2.0 J 1.0 J 0.50 J 0.25 J 4.0 J

0.50 J

A brass wire 2.0 m long and 2.0 mm in diameter supports a 10.0-kg fixture. By what distance did this fixture stretch the wire? Young's modulus for brass is 10 × 1010 N/m2. 0.11 mm 0.22 mm 0.33 mm 0.62 mm

0.62 mm

A 1500-kg car moving at 25 m/s hits an initially uncompressed horizontal ideal spring with spring constant (force constant) of 2.0 × 106 N/m. What is the maximum distance the spring compresses? 0.17 m 0.34 m 0.51 m 0.68 m

0.68 m

When a fan is turned off, its angular speed decreases from 10 rad/s to 6.3 rad/s in 5.0 s. What is the magnitude of the average angular acceleration of the fan? 0.86 rad/s2 0.74 rad/s2 0.37 rad/s2 11 rad/s2 1.2 rad/s2

0.74 rad/s2

An aluminum rod is 10.0 cm long and a steel rod is 80.0 cm long when both rods are at a temperature of 15°C. Both rods have the same diameter. The rods are now joined end-to-end to form a rod 90.0 cm long. If the temperature is now raised from 15°C to 90°C, what is the increase in the length of the joined rod? The coefficient of linear expansion of aluminum is 2.4 × 10-5 K-1 and that of steel is 1.2 × 10-5 K-1. 0.90 mm 0.81 mm 0.72 mm 0.63 mm 0.99 mm

0.90 mm

Which two temperature changes are equivalent? 1 K = 1 F° 1 F° = 1 C° 1 C° = 1 K None of these

1 C° = 1 K

A 15-kg child is sitting on a playground teeter-totter, 1.5 m from the pivot. What is the minimum distance, on the other side of the pivot, such that a 220-N force will make the child lift off the ground? 1.0 m 1.5 m 0.10 m 9.8 m 2.4 m

1.0 m

A large vat contains 1.000 L of water at 20°C. What volume will this water occupy when it is heated up to 80°C? Water has a volume expansion coefficient of 210 × 10-6 K-1. 1.600 L 1.013 L 0.987 L 0.9987 L

1.013 L

The Tonga Trench in the Pacific Ocean is 36,000 feet deep. Assuming that sea water has an average density of 1.04 g/cm3, calculate the absolute (total) pressure at the bottom of the trench in atmospheres. (1.00 in = 2.54 cm, 1.00 atm = 1.01 × 105 Pa) 1.1 × 103 atm 1.1 × 108 atm 1.1 × 105 atm 1.1 × 106 atm 2.1 atm

1.1 × 103 atm

A 320-g air track cart traveling at 1.25 m/s suddenly collides elastically with a stationary 270-g cart. What is the speed of the 270-g cart just after the collision? 0.678 m/s 0.106 m/s 1.36 m/s 1.14 m/s 2.72 m/s

1.36 m/s

A solid uniform disk is rolling without slipping along a horizontal surface with a speed of 4.5 m/s when it starts up a ramp that makes an angle of 25° with the horizontal. What is the speed of the disk after it has rolled 3.0 m up as measured along the surface of the ramp? 4.0 m/s 1.9 m/s 2.1 m/s 6.8 m/s 8.0 m/s

1.9 m/s

A string is wrapped tightly around a fixed pulley that has a moment of inertia of 0.0352 kg m2 and a radius of 12.5 cm. A mass of 423 g is attached to the free end of the string. With the string vertical and taut, the mass is gently released so it can descend under the influence of gravity. As the mass descends, the string unwinds and causes the pulley to rotate, but does not slip on the pulley. What is the speed of the mass after it has fallen through 1.25 m? 2.00 m/s 2.28 m/s 1.97 m/s 3.94 m/s 4.95 m/s

1.97 m/s

A small but dense 2.0-kg stone is attached to one end of a very light rod that is 1.2 m long. The other end of the rod is attached to a frictionless pivot. The rod is raised until it is vertical, with the stone above the pivot. The rod is released and the stone moves in a vertical circle with no air resistance. What is the tension in the rod as the stone moves through the bottom of the circle? 20 N 40 N 60 N 80 N 100 N

100 N

A glass flask has a volume of 500 mL at a temperature of 20° C. The flask contains 492 mL of mercury at an equilibrium temperature of 20°C. The temperature is raised until the mercury reaches the 500 mL reference mark. At what temperature does this occur? The coefficients of volume expansion of mercury and glass are 18 ×10-5 K-1 (mercury) and 2.0 ×10-5 K-1 (glass). 120°C 110°C 100°C 140°C 130°C

120°C

A pencil that is 15.7 cm long is released from a vertical position with the eraser end resting on a table. The eraser does not slip as it tips over. Treat the pencil like a uniform rod. What is the angular speed of the pencil just before it hits the table? 13.7 rad/s 7.23 rad/s 3.70 rad/s 24.5 rad/s 16.8 rad/s

13.7 rad/s

A 550-g ball traveling at 8.0 m/s undergoes a sudden head-on elastic collision with a 250-g ball traveling toward it also at 8.0 m/s. What is the speed of the 250-g mass just after the collision? 15 m/s 8.0 m/s 4.0 m/s 14 m/s 0 m/s

14 m/s

An object having a fixed emissivity of 0.725 radiates heat at a rate of 10 W when it is at an absolute temperature T. If its temperature is doubled to 2T, at what rate will it now radiate? 20 W 40 W 80 W 160 W 320 W

160 W

How many grams of ethanol (density 0.80 g/cm3) should be added to 5.0 g of chloroform (density 1.5 g/cm3) if the resulting mixture is to have a density of 1.2 g/cm3? Assume that the fluids do not change their volumes when they are mixed. 2.0 g 2.4 g 1.8 g 4.4 g 1.6 g

2.0 g

A 2.0-kg mass moving at 5.0 m/s suddenly collides head-on with a 3.0-kg mass at rest. If the collision is perfectly inelastic, what is the speed of the masses just after the collision? 10 m/s 2.5 m/s 2.0 m/s 0 m/s, since the collision is inelastic

2.0 m/s

How many joules of energy are used by a 1.0-hp motor that runs for 1.0 hour? (1 hp = 746 W) 3.6 kJ 2.7 MJ 45 kJ 4.8 J

2.7 MJ

Two identical objects are placed in a room with a temperature of 20°C. Object A has a temperature of 50°C, while object B has a temperature of 90°C. What is the ratio of the net power emitted by object B to the power emitted by object A? 1.7 2.8 81 17 21

2.8

A 200-N object floats with three-fourths of its volume beneath the surface of the water. What is the buoyant force on the object? The density of water is 1000 kg/m3. 50 N 150 N 200 N 267 N It cannot be determined because we do not know the volume of the object.

200 N

The temperature changes from 35°F during the night to 75°F during the day. What is the temperature change on the Celsius scale? 72 C° 40 C° 32 C° 22 C°

22 C°

A 0.140-kg baseball is dropped from rest. It has a speed of 1.20 m/s just before it hits the ground, and it rebounds with an upward speed of 1.00 m/s. The ball is in contact with the ground for 0.0140 s. What is the average force exerted by the ground on the ball during the time of contact? 2.00 N upwards 2.00 N downwards 22.0 N upwards 22.0 N downwards 0.00 N

22.0 N upwards

What is the net power needed to change the speed of a 1600-kg sport utility vehicle from 15.0 m/s to 40.0 m/s in 4.00 seconds? 100 kW 10.0 kW 140 kW 14.0 kW 275 kW

275 kW

A beaker of negligible heat capacity contains 456 g of ice at -25.0°C. A lab technician begins to supply heat to the container at the rate of 1000 J/min. How long after starting will the ice begin to melt, assuming all of the ice has the same temperature? The specific heat of ice is 2090 J/kg K and the latent heat of fusion of water is 33.5 × 104 J/kg.

28.3 min

The temperature in your classroom is closest to 68 K. 68°C. 50°C. 295 K.

295 K.

An ideal gas is held in a container of volume V at pressure p. The rms speed of a gas molecule under these conditions is v. If now the volume and pressure are changed to 2V and 2p, the rms speed of a molecule will be v/2 v 2v 4v v/4

2v

If the temperature of an ideal gas is increased from 20°C to 40°C, by what percent does the speed of the molecules increase? 3% 30% 70% 100%

3%

Water is flowing in a drainage channel of rectangular cross-section. The width of the channel is 15 m, the depth of water is 8.0 m, and the speed of the flow is 2.5 m/s. What is the mass flow rate of the water? The density of water is 1000 kg/m3. 2.0 × 105 kg/s 2.0 × 103 kg/s 3.0 × 105 kg/s 3.0 × 103 kg/s 3.0 × 102 kg/s

3.0 × 105 kg/s

The coefficient of linear expansion of copper is 17 × 10-6 K-1 and that of steel is 12 × 10-6 K-1. At 12°C a steel rod has a diameter of 2.540 cm and a copper pipe has a diameter of 2.536 cm. If they are heated together to a higher temperature, which one of the following quantities is closest to the common temperature at which the steel rod will fit snugly in the copper pipe? 310°C 330°C 340°C 350°C 380°C

330°C

A 50-kg bucket of concrete is suspended from a steel wire that is 1.0 mm in diameter 1.0 mm and 11.2 m long. What distance will the wire stretch? Young's modulus for steel is 2.0 x 1011 Pa.

35 mm

Express a body temperature 98.6°F in Celsius degrees. 37.0°C 45.5°C 66.6°C 72.6°C

37.0°C

A polar bear of mass 200 kg stands on an ice floe that is a uniform 1.0 m thick. What is the minimum area of the floe that will just support the bear in saltwater of density 1030 kg/m3? The density of ice is 980 kg/m3. 1.0 m2 2.0 m2 3.0 m2 4.0 m2

4.0 m2

A chicken is running in a circular path with an angular speed of 1.52 rad/s. How long does it take the chicken to complete one revolution? 4.13 s 2.07 s 118 s 4.77 s 8.26 s

4.13 s

A shear force of 400 N is applied to one face of an aluminum cube having sides of 30 cm each. What is the resulting displacement of this face of the cube if the opposite face is held fixed? The shear modulus for aluminum is 2.5 × 1010 N/m2. 1.9 × 10-8 m 4.4 × 10-8 m 5.3 × 10-8 m 8.2 × 10-8 m

5.3 × 10-8 m

How long does it take for a rotating object to speed up from 15.0 rad/s to 33.3 rad/s if it has a uniform angular acceleration of 3.45 rad/s2? 4.35 s 5.30 s 9.57 s 10.6 s 63.1 s

5.30 s

A vertical 30-cm steel rod, 1.0 cm in diameter, supports a 300-kg mass. What is the change in length of the rod caused by this mass? Young's modulus for steel is 2.0 × 1011 N/m2. 5.6 × 10-5 m 6.5 × 10-5 m 5.6 × 10-6 m 6.5 × 10-6 m 6.5 × 10-4 m

5.6 × 10-5 m

If 4.0 J of work are performed in stretching an ideal spring with a spring constant (force constant) of 2500 N/m, by what distance is the spring stretched? 3.2 cm 3.2 m 0.3 cm 5.7 m 5.7 cm

5.7 cm

A hoop with a mass of 2.75 kg is rolling without slipping along a horizontal surface with a speed of 4.5 m/s when it starts down a ramp that makes an angle of 25° below the horizontal. What is the forward speed of the hoop after it has rolled 3.0 m down as measured along the surface of the ramp? 4.9 m/s 6.3 m/s 5.2 m/s 5.7 m/s 8.0 m/s

5.7 m/s

A barge with vertical sides is 10 m wide and 60 m long and is floating in fresh water of density 1000 kg/m3. How much deeper into the water does the barge sink when 3.0 x 105 kg of coal are loaded on the barge? 25 cm 50 cm 75 cm 1.0 m 1.5 m

50 cm

Which requires more work, increasing a car's speed from 0 mph to 30 mph or from 50 mph to 60 mph? 0 mph to 30 mph 50 mph to 60 mph It is the same in both cases.

50 mph to 60 mph

A runner generates 1260 W of thermal energy. If this heat has to be removed only by evaporation, how much water does this runner lose in 15 minutes of running? The latent heat of vaporization of water is 22.6 × 105 J/kg. 50 g 500 g 35 g 350 g 40 g

500 g

A 1000-kg car is moving at 15 km/h. If a 2000-kg truck has 23 times the kinetic energy of the car, how fast is the truck moving? 51 km/h 72 km/h 61 km/h 41 km/h

51 km/h

A 13,000-N vehicle is to be lifted by a 25-cm diameter hydraulic piston. What force needs to be applied to a 5.0 cm diameter piston to accomplish this? Assume the pistons each have negligible weight. 260 N 520 N 2600 N 5200 N

520 N

A 1.00-m3 object floats in water with 20.0% of its volume above the waterline. What does the object weigh out of the water? The density of water is 1000 kg/m3. 1,960 N 7,840 N 9,800 N 11,800 N

7,840 N

A 900-kg car traveling 30.0° south of east at 12.0 m/s suddenly collides with a 750-kg car traveling north at 17.0 m/s. The cars stick together after colliding. What is the speed of the wreckage just after the collision? 7.21 m/s 12.2 m/s 20.4 m/s 25.0 m/s 17.3 m/s

7.21 m/s

A 1938 nickel has a diameter of 21.21 mm, a thickness of 1.95 mm, and weighs 0.04905 N. What is its density? 1.37 × 10-4 kg/m3 1.82 × 103 kg/m3 19.3 × 103 kg/m3 3.63 × 103 kg/m3 7.26 × 103 kg/m3

7.26 × 103 kg/m3

If the work done to stretch an ideal spring by 4.0 cm is 6.0 J, what is the spring constant (force constant) of this spring? 300 N/m 3000 N/m 3500 N/m 7500 N/m 6000 N/m

7500 N/m

A puck with a mass m1 = 50 g moving at 1.0 m/s approaches a stationary puck with a mass m2 = 100 g on a frictionless air table, and they undergo a sudden two-dimensional elastic collision. After the collision, both pucks have identical speeds, but travel in different directions. What is the angle between the original and final paths of puck with mass m1? 30° 60° 90° 120° 150°

90°

A typical incandescent light bulb consumes 75 W of power and has a mass of 30 g. You want to save electrical energy by dropping the bulb from a height great enough so that the kinetic energy of the bulb when it reaches the floor will be the same as the energy it took to keep the bulb on for 1.0 hour. From what height should you drop the bulb, assuming no air resistance and constant g?

920 km

An old LP record that is originally rotating at 33.3 rad/s is given a uniform angular acceleration of 2.15 rad/s2. Through what angle has the record turned when its angular speed reaches 72.0 rad/s? 83.2 rad 316 rad 697 rad 66.8 rad 948 rad

948 rad

Consider a uniform hoop of radius R and mass M rolling without slipping. Which is larger, its translational kinetic energy or its rotational kinetic energy? Translational kinetic energy is larger. Rotational kinetic energy is larger. Both are equal. You need to know the speed of the hoop to tell.

Both are equal.

A mole of diatomic oxygen molecules and a mole of diatomic nitrogen molecules are at STP. Which statements are true about these molecules? (There could be more than one correct choice.) Both gases have the same average molecular speeds. Both gases have the same number of molecules. Both gases have the same average kinetic energy per molecule. Both gases have the same average momentum per molecule.

Both gases have the same number of molecules. Both gases have the same average kinetic energy per molecule.

If the sum of the external forces on an object is zero, then the sum of the external torques on it must also be zero. True False

False

There must be equal amounts of mass on both sides of the center of mass (or center of gravity) of a system. True False

False

A piece of wood is floating in a bathtub. A second piece of wood sits on top of the first piece, and does not touch the water. If the top piece is taken off and placed in the water, what happens to the water level in the tub? It goes up. It goes down. It does not change. It cannot be determined without knowing the volumes of the two pieces of wood.

It does not change.

A piece of iron rests on top of a piece of wood floating in a bathtub. If the iron is removed from the wood, and kept out of the water, what happens to the water level in the tub? It goes up. It goes down. It does not change. It is impossible to determine from the information given.

It goes down.

Two solid spheres are made from the same material, but one has twice the diameter of the other. Which sphere will have the greater bulk modulus? the larger one the smaller one It will be the same for both spheres.

It will be the same for both spheres.

Two wires are made out of the same metal, but one wire is twice as long as the other wire. Which wire will have the greatest elastic modulus? the shorter wire the longer wire It will be the same for both wires.

It will be the same for both wires.

A piece of iron sinks to the bottom of a lake where the pressure is 21 times what it is at the surface. Which statement best describes what happens to the density of that piece of iron? There has been no change in the density of the iron. Its density decreases slightly. Its density increases slightly. Its density becomes 21 times greater than what it was at the surface. Its density becomes 1/21 what it was at the surface.

Its density increases slightly.

A piece of iron sinks to the bottom of a lake where the pressure is 21 times what it is at the surface of the lake. Which statement best describes what happens to the volume of that piece of iron? There has been no change in the volume of the iron. Its volume decreases slightly. Its volume increases slightly. Its volume becomes 21 times greater than at the surface. Its volume becomes 1/21 what it was at the surface.

Its volume decreases slightly.

A thermally isolated system is made up of a hot piece of aluminum and a cold piece of copper, with the aluminum and the copper in thermal contact. The specific heat capacity of aluminum is more than double that of copper. Which object experiences the greater magnitude gain or loss of heat during the time the system takes to reach thermal equilibrium? the aluminum the copper Neither one; both of them experience the same size gain or loss of heat. It is impossible to tell without knowing the masses. It is impossible to tell without knowing the volumes.

Neither one; both of them experience the same size gain or loss of heat.

A very light ping-pong ball moving east at a speed of 4 m/s collides with a very heavy stationary bowling ball. The Ping-Pong ball bounces back to the west, and the bowling ball moves very slowly to the east. Which object experiences the greater magnitude impulse during the collision? Neither; both experienced the same magnitude impulse. the Ping-Pong ball the bowling ball It is impossible to tell since the actual mass values are not given. It is impossible to tell since the velocities after the collision are unknown.

Neither; both experienced the same magnitude impulse.

A firecracker explodes in midair and breaks up into many fragments. Which of the following statements are true regarding conditions immediately before and immediately after the explosion: I. The total momentum of the fragments is equal to the original momentum of the firecracker. II. The total kinetic energy of the fragments is equal to the original kinetic energy of the firecracker. Statement I only Statement II only Both Statement I and Statement II Neither statement is true.

Statement I only

A disk and a hoop of the same mass and radius are released at the same time at the top of an inclined plane. If both are uniform, which one reaches the bottom of the incline first if there is no slipping? The hoop The disk Both reach the bottom at the same time.

The disk

A fixed container holds oxygen and helium gases at the same temperature. Which of the following statements are correct? (There could be more than one correct choice.) The oxygen molecules have the greater average kinetic energy. The helium molecules have the greater average kinetic energy. The oxygen molecules have the greater speed. The helium molecules have the greater speed. The helium molecules have the same average kinetic as the oxygen molecules.

The helium molecules have the greater speed. The helium molecules have the same average kinetic as the oxygen molecules.

A heavy stone and a light stone are released from rest in such away that they both have the same amount of gravitational potential energy just as they are released. Air resistance is negligibly small. Which of the following statements about these stones are correct? (There could be more than one correct choice.) The initial height of the light stone is greater than the initial height of the heavy stone. The stones must have been released from the same height. The stones both have the same speed just as they reach the ground. Just as it reaches the ground, the light stone is traveling faster than the heavy stone. The stones both have the same kinetic energy just as they reach the ground.

The initial height of the light stone is greater than the initial height of the heavy stone. Just as it reaches the ground, the light stone is traveling faster than the heavy stone. The stones both have the same kinetic energy just as they reach the ground.

A spherical ball of lead (density 11.3 g/cm3) is placed in a tub of mercury (density 13.6 g/cm3). Which answer best describes the result? The lead ball will float with about 83% of its volume above the surface of the mercury. The lead ball will float with its top exactly even with the surface of the mercury. The lead ball will float with about 17% of its volume above the surface of the mercury. The lead will sink to the bottom of the mercury.

The lead ball will float with about 17% of its volume above the surface of the mercury.

A heavy dart and a light dart are launched vertically by identical ideal springs. Both springs were initially compressed by the same amount. There is no significant air resistance. Which of the following statements about these darts are correct? (There could be more than one correct choice.) The heavy dart goes higher than the light dart. The light dart goes higher than the heavy dart. Both darts reach the same maximum height. At the maximum height, both darts have the same gravitational potential energy. Both darts began moving upward with the same initial speed.

The light dart goes higher than the heavy dart. At the maximum height, both darts have the same gravitational potential energy.

A very elastic rubber ball is dropped from a certain height and hits the floor with a downward speed v. Since it is so elastic, the ball bounces back with the same speed v going upward. Which of the following statements about the bounce are correct? (There could be more than one correct choice.) The ball had the same momentum just before and just after the bounce. The magnitude of the ball's momentum was the same just before and just after the bounce. The ball's momentum was conserved during the bounce. None of these statements are correct.

The magnitude of the ball's momentum was the same just before and just after the bounce.

You throw a baseball straight up. Compare the sign of the work done by gravity while the ball goes up with the sign of the work done by gravity while it goes down. The work is positive on the way up and positive on the way down. The work is positive on the way up and negative on the way down. The work is negative on the way up and positive on the way down. The work is negative on the way up and on the way down because gravity is always downward.

The work is negative on the way up and positive on the way down.

Three cars (car F, car G, and car H) are moving with the same speed and slam on their brakes. The most massive car is car F, and the least massive is car H. If the tires of all three cars have identical coefficients of kinetic friction with the road surface, which car travels the longest distance to skid to a stop? They all travel the same distance in stopping. Car F Car G Car H

They all travel the same distance in stopping.

In a collision between two unequal masses, which mass receives a greater magnitude impulse? the larger mass the smaller mass They receive equal impulses.

They receive equal impulses

If an object remains at rest, then the sum of both the external torques and the external forces on the object must be zero. True False

True

In a police rifle test, a 15-g bullet traveling 213 m/s in a vertical direction suddenly buries itself in a 2.4-kg block of wood at rest directly above it. As a result, the bullet-block combination moves vertically upward. (a) Determine the velocity of the bullet-block combination just after the impact. (b) Determine the maximum height reached by the bullet/block combination. (c) Is kinetic energy conserved in this collision?

a) 1.32 m/s b) 8.8m c) no

A 7.0-kg pipe is hung from a steel wire that is 2.5 m long and has a diameter of 0.75 mm. Young's modulus for steel is 2.0 × 1011 N/m2. (a) By what distance does the wire stretch? (b) If the wire diameter were doubled, what would be the stretch?

a)1.94x10^-3 m b)4.854x10^-4m

An 82-kg painter stands on a long horizontal board 1.55 m from one end. This 27-kg board is uniform, 5.5 m long, and supported at each end by vertical posts. (a) What is the magnitude of the total force provided by both posts? (b) With what force does the post that is closest to the painter push upward on the board?

a)1068.2N b)709N

The process in which heat flows by the mass movement of molecules from one place to another is known as conduction. convection. radiation.

convection.

In a game of pool, the white cue ball hits the #5 ball and stops, while the #5 ball moves away with the same velocity as the cue ball had originally. Both balls have the same mass. This type of collision is somewhat inelastic. elastic. completely inelastic.

elastic.

Identical forces act for the same length of time on two different objects. The magnitude of the change in momentum of the lighter object is smaller than the magnitude of the change in momentum of the larger mass, but not zero. larger than the magnitude of the change in momentum of the larger mass. exactly equal to the magnitude of the change in momentum of the larger mass. zero. There is not enough information to answer the question.

exactly equal to the magnitude of the change in momentum of the larger mass.

A boat loaded with rocks is floating in a swimming pool. If the rocks are thrown into the pool, the water level in the pool, after the rocks have settled to the bottom, rises. falls. stays the same.

falls.

A steel ball sinks in water but floats in a pool of mercury, which is much denser than water. Where is the buoyant force on the ball greater? floating on the mercury submerged in the water It is the same in both cases. It cannot be determined from the information given.

floating on the mercury

A stone is held at a height h above the ground. A second stone with four times the mass of the first one is held at the same height. The gravitational potential energy of the second stone compared to that of the first stone is one-fourth as much. one-half as much. twice as much. four times as much. the same.

four times as much.

Joe and Bill throw identical balls vertically upward. Joe throws his ball with an initial speed twice as high as Bill. If there is no air resistance, the maximum height of Joe's ball will be four times that of Bill's ball. two times that of Bill's ball. equal to that of Bill's ball. eight times that of Bill's ball. roughly 1.4 times that of Bill's ball.

four times that of Bill's ball.

Consider a brick that is totally immersed in water, with the long edge of the brick vertical. The pressure on the brick is the same on all surfaces of the brick. greatest on the face with largest area. greatest on the top of the brick. greatest on the sides of the brick. greatest on the bottom of the brick.

greatest on the bottom of the brick.

Which one of the following would be expected to have the smallest bulk modulus? liquid mercury liquid water helium vapor solid iron solid uranium

helium vapor

A person sits on a freely spinning lab stool that has no friction in its axle. When this person extends her arms, her moment of inertia decreases and her angular speed increases. her moment of inertia decreases and her angular speed decreases. her moment of inertia increases and her angular speed increases. her moment of inertia increases and her angular speed decreases. her moment of inertia increases and her angular speed remains the same.

her moment of inertia increases and her angular speed decreases.

If the absolute temperature of an object is tripled, the thermal power radiated by this object (assuming that its emissivity and size are not affected by the temperature change) will increase by a factor of 3. increase by a factor of 9. increase by a factor of 18. increase by a factor of 27. increase by a factor of 81.

increase by a factor of 81.

A railroad car collides with and sticks to an identical railroad car that is initially at rest. After the collision, the kinetic energy of the system is the same as before. is half as much as before. is one third as much as before. is one fourth as much as before. is one quarter as much as before.

is half as much as before.

Oxygen molecules are 16 times more massive than hydrogen molecules. At a given temperature, the average molecular kinetic energy of oxygen molecules, compared to that of hydrogen molecules, is greater. is less. is the same. cannot be determined without knowing the pressure and volume.

is the same.

Suppose a uniform solid sphere of mass M and radius R rolls without slipping down an inclined plane starting from rest. The linear velocity of the sphere at the bottom of the incline depends on the mass of the sphere. the radius of the sphere. both the mass and the radius of the sphere. neither the mass nor the radius of the sphere.

neither the mass nor the radius of the sphere.

A wooden block contains some nails so that its density is exactly equal to that of water. If it is placed in a tank of water and released from rest when it is completely submerged, it will rise to the surface. sink to the bottom. remain where it is released.

remain where it is released.

If you wanted to know how much the temperature of a particular piece of material would rise when a known amount of heat was added to it, which of the following quantities would be most helpful to know? initial temperature specific heat density coefficient of linear expansion thermal conductivity

specific heat

A solid sphere, solid cylinder, and a hollow pipe all have equal masses and radii. If the three of them are released simultaneously at the top of an inclined plane and do not slip, which one will reach the bottom first? sphere pipe cylinder The pipe and cylinder arrive together before the sphere. They all reach the bottom at the same time.

sphere

A disk, a hoop, and a solid sphere are released at the same time at the top of an inclined plane. They are all uniform and roll without slipping. In what order do they reach the bottom? disk, hoop, sphere hoop, sphere, disk sphere, disk, hoop sphere, hoop, disk hoop, disk, sphere

sphere, disk, hoop

When you blow some air above a paper strip, the paper rises. This happens because the air above the paper moves faster and the pressure is higher. the air above the paper moves faster and the pressure is lower. the air above the paper moves faster and the pressure remains constant. the air above the paper moves slower and the pressure is higher. the air above the paper moves slower and the pressure is lower.

the air above the paper moves faster and the pressure is lower.

The absolute temperature of an ideal gas is directly proportional to which of the following quantities? the average speed of its molecules the average momentum of its molecules the average kinetic energy of its molecules the mass of its molecules It is proportional to all of these quantities.

the average kinetic energy of its molecules

Two equal-magnitude forces are applied to a door at the doorknob. The first force is applied perpendicular to the door, and the second force is applied at 30° to the plane of the door. Which force exerts the greater torque about the door hinge? the first force (applied perpendicular to the door) the second force (applied at an angle) Both forces exert equal non-zero torques. Both forces exert zero torque.

the first force (applied perpendicular to the door)

Two forces produce equal torques on a door about the door hinge. The first force is applied at the midpoint of the door; the second force is applied at the doorknob. Both forces are applied perpendicular to the door. Which force has a greater magnitude? the first force (at the midpoint) the second force (at the doorknob) The two forces are equal.

the first force (at the midpoint)

Two objects of different mass have equal, non-zero kinetic energies. Which object has the greater magnitude momentum? the heavier object the lighter object They both have the same magnitude momentum.

the heavier object

A 50-cm3 block of wood is floating on water, and a 50-cm3 chunk of iron is totally submerged in the water. Which one has the greater buoyant force on it? the wood the iron Both have the same buoyant force. It cannot be determined without knowing their densities.

the iron

Two objects of different masses have momentum of equal, non-zero magnitude. Which object has more kinetic energy? the heavier object the lighter object They both have the same kinetic energy.

the lighter object

A merry-go-round spins freely when Diego moves quickly to the center along a radius of the merry-go-round. As he does this, it is true to say that the moment of inertia of the system decreases and the angular speed increases. the moment of inertia of the system decreases and the angular speed decreases. the moment of inertia of the system decreases and the angular speed remains the same. the moment of inertia of the system increases and the angular speed increases. the moment of inertia of the system increases and the angular speed decreases.

the moment of inertia of the system decreases and the angular speed increases.

As one stretches a metal wire, which condition is reached first? the elastic limit the breaking point the proportional limit

the proportional limit

Suppose a solid uniform sphere of mass M and radius R rolls without slipping down an inclined plane starting from rest. The angular velocity of the sphere at the bottom of the incline depends on the mass of the sphere. the radius of the sphere. both the mass and the radius of the sphere. neither the mass nor the radius of the sphere.

the radius of the sphere.

Tensile strain is the ratio of the change in length to the original length. the stress per unit area. the applied force per unit area. the ratio of stress to elastic modulus.

the ratio of the change in length to the original length.

When a car is weighed, it is driven slowly on a horizontal floor over a scale that records a reading as the front wheels go over the scale, and then records a second reading as the rear wheels go over the scale. The weight of the car is equal to the weight under the front wheels. the weight under the rear wheels. the average of the two weights. the sum of the two weights. the difference of the two weights.

the sum of the two weights.