Physics Final (Problems)

A ball (#1) is thrown horizontally from the top of a tower at the same instant an identical ball (#2) is dropped vertically. Which object is traveling faster when it hits the level ground below? (neglect air resistance)

#1

M1=2.0kg and is located at position (0, 0); M2=6.0kg and is located at position (10, 0). Where should M3 be located so that it has a net gravitational force of zero due to the other two masses?

(3.7, 0)

A bowling ball (mass=6.0kg) strikes a pin (0.5 kg) with a force of 8.0 N. If the ball is traveling in the positive direction, what is the acceleration of the ball while it is in contact with the pin? Answer in m/s2

-1.3

For this problem refer to Graph #2, which shows a v-t graph of the motion of an object. he graph begins at t=0 sec and ends at t=25 sec. When reading the graph assume that constant velocities occur at whole numbers (for instance -9 m/s not -8.9m/s) and that changes in motion occur at whole number times. What is the acceleration in m/s2, of the object at 13.0 seconds?

-1.8

A 50-g ball moving at +10m/s collides head-on with a stationary ball of mass 100g. The collision is completely elastic. What is the velocity of each ball (in m/s) immediately after the collision? The first number is the velocity of the 50-g ball

-3.3; 6.7

For this problem use graph #1. What is the displacement in meters, of the object from t=0 to t=9.4 sec?

-3.6

While a person lifts a book of mass 2.0 kg from the floor to a tabletop. 1.5 m above the floor, how much work, in joules, does the gravitational force do on the book?

-30

An airplane pilot fell 380 m after jumping from an aircraft without his parachute opening. He landed in a showbank, creating a crater 1.5 m deep, but survived with only minor injuries. Assuming the pilots mass was 82 kg ans his terminal velocity was 41 m/s, find the work done by the snow in bring him to rest, in joules

-7.0 E4

A rescue plan wants to drop supplies to isolated mountain climbers on a rocky ridge 235 m below. If the plane is traveling horizontally with a speed of 250 km/h (69.4 m/s), and if the plane releases the supplies a horizontal distance of 245 m in advance of the climbers, at what vertical velocity should the supplies be given so that they arrive precisely at the climbers' position? use -9.8m/s2

-8.41

Indiana Jones exerts a force of 750.0 N over a distance of 12 m to slow down and then stop a large rolling boulder. How much work has Jones done on the boulder?

-9000J

A boat, whose speed in still water is 2.0m/s, must cross a 240 m wide river and arrive at a point 120 m upstream from where it starts. To do so, the pilot must head the boat at a 53 degree upstream angle (relative to the shore). What is the speed of the river's current in m/s?

.4

Two carts with masses of 8.0 kg and 3.5 kg move in opposite directions respectively. The carts stick together after colliding head on. Find the final speed of the two carts in m/s.

.43

A ranger in a national park is driving 72 km/h when a deer jumps onto the road 60 m ahead of the vehicle. After a reaction time of t sec, the ranger applies the brakes to produce an acceleration of -4m/s2. What is the maximum reaction time (in sec) allowed if the ranger is to avoid hitting the deer?

.5

An object of mass m is traveling at a constant speed v in a circular path of radius r. How much work is done by the centripetal force during one half of a revolution?

0

For this problem use graph #1. At what time, in seconds, is the velocity of the object zero?

0-1.8, and 4.7

As the earth spins on its axis, what is the centripetal acceleration of a person living at the equator? Answer in m/s2

0.034

an object is launched from the ground with an initial velocity and angle such that the maximum height achieved is equal to the range of the projectile. The tangent of the launch angle is equal to

1

Refer to figure 9 for this problem. If F=60N, M1=20kg, M2=10kg, and the coefficient of kinetic friction between the blocks and the table is 0.10, find the acceleration of the blocks in m/s2. (use g=N/kg)

1.0

Consider a drag-race car with tires in contact with an asphalt surface. Assume a constant acceleration and no slipping of tires. If the car travels 1.0 km in 12 sec starting from rest, what is the coefficient of static friction?

1.4

In the figure below, MA=MB, and the coefficient of friction between MA and the inclined plane is 0.10. The angle of incline fata is 37 degrees. Find the acceleration of the system. Answer in m/s2

1.6

Object 1 moves towards Object 2, whose mass is twice that of Object 1 and which is initially at rest. After their impact, the objects lock together and move with what fraction of Object 1's initial kinetic energy?

1/3

When the frictionless system shown above is accelerated by an applied force of magnitude F, the tension in the string between the blocks is

1/3

A truck's speed increases uniformly from 12.0km/h to 60km/h in 20.0 sec. Determine the average speed in m/s

10.0

In figure 2, F1=7.5N and F2=13.6N. Find the resultant force in Newtons if the angle between the two force vectors is 130 degrees. The angle measurements below, in brackets, are measured clockwise from vector F1

10.5 [96.8]

A stone is thrown vertically upward with a speed of 15m/s from the edge of a cliff 100 m high. What is the height of the stone (measured from the horizontal ground below) after 3.0 sec? Answer in meters use g=-10m/s2

100

a plane flying horizontally at a speed of 50m/s and at an elevation of 160 m drops a package. Two seconds later it drops a second package. How far apart will the two packages land on the ground?

100m

A person who weighs 800N steps onto a scale that is on the floor of an elevator car. If the elevator accelerates upward at a rate of 5m/s2, what will the scale read?

1200N

A roller coaster car passes a point 35 m above the low point of the ride with a speed of 20m/s. If the ride is frictionless, what will be the speed of the roller coaster car at the top of the next rise, which is 45 m above the low point? Answer in m/s.

14

At what velocity, in m/s, should a ball be thrown at 45 degree angle so that it hits a target that is 20 meters away and placed at the same height?

14

A projectile is launched at an angle of 45 degrees with a velocity of 200m/s. If air resistance is neglected, the magnitude of the horizontal velocity of the projectile at the time it reaches its maximum altitude is equal to

141m/s

a steel ball bearing is launched horizontally with a speed of 9.0m/s from a height of 7.2 m above the level ground below. What is the speed of the ball bearing Just before the ball bearing hits the ground, in m/s?

15

A bowling ball (mass=6.0kg) strikes a pin (0.5 kg) with a force of 8.0 N. If the ball is traveling in the positive direction, what is the acceleration of the pin while it is in contact with the ball? Answer in m/s2

16

Two astronauts, one of mass 50.0 kg and the other of mass 75.0 kg, are initially at rest in outer space, They then push each other apart. How far apart are they (in meters) when the lighter astronaut has moved 10.0 meters?

16.7

An arrow of mass 20.0 g is shot horizontally into a bale of hay, striking the hay with a velocity of 60.0 m/s. It penetrates a depth of 20 cm before stopping. What is the magnitude of the average stopping force acting on the arrow? Answer in Newtons.

180

A projected space station consists of a circular tube that will rotate about its center (like a tubular bicycle tire). The circle formed by the tube has a diameter of about 1.1km. What must be the rotation speed (revolutions per day) if an equal effect to gravity at the surface of the Earth (1.0g) is to be felt?

1825

The table above shows information from the "Acceleration Lab". What was the velocity of the car at 60cm? assume the lab was preformed as we did it in class

196

A 60 cm rope is tied to the handle of a bucket which is then whirled in a vertical circle. The mass of the bucket is 3kg. At the lowest point in the its path, the tension in the rope is 50N. What is the speed of the bucket, in m/s? Use g=10N/kg

2

Projectiles A and B are launched from the ground and return to the same vertical height. Projectile A is launched with a muzzle velocity VA and travels a horizontal distance XA. Projectile B is launched with muzzle velocity 2VA and travels a horizontal distance XB. Neglecting air resistance, what is the ration XB/XA

2

The figure below shows overhead views of four situations in which forces act on a block that lies on a frictionless floor. If the force magnitudes are chose properly, in which situation(s) is it possible that the block is moving with a constant velocity?

2, 4

A pendulum bob 100 cm long is released from rest at an angle 37 degrees from the vertical. How fast is the pendulum bob traveling when it reaches its lowest point, in m/s? Use g=10N/kg

2.0

a stopper on the end of a string revolves with a frequency of 0.50 Hz. What is the period of rotation?

2.0 sec

A 60 cm rope is tied to the handle of a bucket which is then whirled in a vertical circle. The mass of the bucket is 3kg. What is the critical speed in m/s, below which the rope would become slack (zero tension) when the bucket reaches the highest point in the circle?

2.4

A wrench falls from a helicopter that is rising steadily at 5.00m/s. After 2.00 seconds, how far below the helicopter is the wrench (in meters)?

20

As a rock of mass 4.0kg drops from the edge of a 40-meter high cliff, it experiences air resistance whose average strength during the descent is 20N. At what speed, in m/s, will the rock hit the ground?

20

In the figure below, M1= 20kg, M2=5.0kg, M3=10kg, F=70N. Find the force, in Newtons, of block M2 on block M3. Assume a frictionless surface. (use g=10N/kg)

20

In the figure below, M=6.0kg and m=3.0kg. What is the tension in the string in Newtons if the surface is frictionless? Use g=10N/kg (magnitude)

20

Starting from rest, a vehicle accelerates on a straight level road at the rate of 4.0 m/s2 for 5.0 seconds. What is the speed of the vehicle at the end of the time interval? answer in m/s

20

a cannonball is shot toward a castle wall at an initial speed of 100m/s at an angle of 37 degrees above this horizontal. The castle wall is 160m away and 80 m tall. By how much, in meters, will the cannonball clear the wall vertically (assume level ground)?

20

For a car traveling with a speed of 14m/s around a curve of radius 50m, what is the angle at which the road should be banked so that no friction is required to keep the car in its circular path? Answer in degrees.

22

For this graph refer to Graph #2, which shows a v-t graph of the motion of an object. The graph begins at t=0 sec and ends at t=25 sec. When reading the graph assume that constant velocities occur at whole numbers (for instance -9 m/s not -8.9m/s) and that changes in motion occur at whole number times. If the object starts at a position of 0.0 meters, at what time, in seconds, does it pass the position of 0.0 meters again?

23.2

consider three point particles, each mass m=3.0 E6 kg, that form an equilateral triangle with side x=2.0m. What is the magnitude of the net force on one of the particles, in Newtons?

260

a projectile is launched at an angle of 45 degrees above the horizontal. It has the following initial velocity components Vox=10m/s and Voy=10m/s. What angle is the displacement vector (above the horizontal) at the high point?

27

the mean distance from Saturn to the sun is 9 times greater than the mean distance from the earth to the sun. How long is the saturn year, in Earth years?

27

A projectile is launched at a velocity of 100 m/s at an angle of 37 degrees above the horizontal. A building is 240 m away. At which height above the ground will the projectile strike the building? answer in meters. Use g=-10m/s2

28

The figure below shows three paths for a football kicked from ground level. Ignoring the affects of air, rank the paths according to initial horizontal velocity component, greatest first.

3, 2, 1

An atomic nucleus initially moving at 410m/s emits an alpha particle in the same direction as its velocity, and the new nucleus slows to 360m/s. If the alpha particle has a mass of 4.0 u and the original nucleus has a mass of 222 u, what speed does the alpha particle have when it is emitted? Answer in m/s X 10^3

3.1

In the figure below, M=6.0kg and m=3.0kg. What is the acceleration of block M in m/s2 if the surface is frictionless? use g=10N/kg (magnitude)

3.3

A geostationary satellite is one that orbits earth such that it is always over the same spot above the equator. Find the height above the earth's surface a geostationary satellite must orbit. Anwser in meters.

3.59 E7

A book is placed on a horizontal board, which is then slowly raised at one end. The book just begins to slide down the board when the angle of the board relative to the horizontal is 37 degrees. What is the coefficient of friction between the book and the board?

3/4

In the figure below, M=6.00kg and m=3.00kg. What is the tension in the string in Newtons if the system is in static equilibrium (not accelerating) due to the static friction between Block 1 and the surface?

30

An Olympic athlete throws a javelin at four different angles (in degrees) above the horizontal: 30, 40, 60, and 80. Each javelin is thrown with the same speed. Neglecting air resistance, which two throws cause the javelin to land the same distance away? Anwser in degrees.

30 and 60

A 60kg basketball player is able to jump 0.80m off the ground. To do this, what force (in Newtons) must he exert against the ground? Assume the person crouches a distance of 0.20 m prior to jumping, and thus the downward force has this distance to act over before he leaves the ground.

3000

Two vectors, of magnitudes of 20 and 50, are added. Which of the following is a possible answer for the magnitude of the resultant?

40

A stone is thrown vertically upward with a speed of 15m/s from the edge of a cliff. What is the total distance that the stone has traveled after 4.00 sec? Answer in meters. Use g=-10m/s

42.5

The mass of Planet X is one-tenth that of the Earth, and its diameter is one-half that of the Earth. The acceleration due to gravity at the surface of planet X is most nearly

4m/s2

A 20 N block is being pushed across a horizontal table by an 18 N force. If the coefficient of kinetic friction between the block and the table is 0.4 find the acceleration of the block, in m/s2.

5

A frictionless inclined plane of length 20 m has a maximum vertical height of 5m. If an object of mass 2kg is placed on the plane, which of the following best approximates the net force it feels?

5 N

a car is traveling 36 km/h on a flat highway. If the coefficient of kinetic friction between the icy road and the tires is 0.1, what is the minimum distance needed for the car to stop, in meters?

50

A 250-kg piano slides 4.0m down a 30 degree incline and is kept from accelerating by a man who is pushing back on it parallel to the incline. The effective coefficient of kinetic friction is 0.40. Calculate the work done on the piano by the force of gravity in Joules.

5000

A helicopter flying at 60m/s horizontally wants to drop a bomb on a car below traveling at 45m/s on a level highway 80m below. At what angle relative to the horizontal should the car be in his sights when the bomb is dropped? answer in degrees

53

A steel ball bearing is launched horizontally with a speed of 9.0m/s from a height of 7.2 m above the level ground below. Just before the ball bearing hits the ground, what is the angle its velocity vector makes relative to the horizontal in degrees?

53

Under the influence of a force, an object of mass 4.0 kg accelerates from 3.0m/s to 6.0m/s in 8.0s. How much work, in joules, was done on the object during this time?

54

The coefficient of static and kinetic frictions between a 3.0-kg box and a desk are 0.40 and 0.30, respectively. What is the net force on the box when a 15-N horizontal force is applied to the box? Answer in Newtons.

6.0

A projectile is launched horizontally with a muzzle velocity of 6.4m/s. what is the horizontal component of the projectile's velocity just before it hits the ground? answer in m/s

6.4

Two lead spheres of mass 1.0kg each are separated from each other by 1.0 m. What is the gravitational force between the two spheres? Answer in Newtons.

6.67 E-11

A student doing the projectile lab fires the projectile horizontally and find that the Vx is 6.8m/s. The same launcher at the same setting is then used to fire the projectile at an angle of 15 degrees. What is V0 (also known as muzzle velocity) at 15 degrees in m/s?

6.8

A 15.0-kg bullet strikes and becomes embedded in a 1.485-kg block of wood placed on a horizontal surface just in front of the gun. If the coefficient of kinetic friction between the block and the surface is 0.200, and the impact drives the block a distance of 10.0m before it comes to rest, what was the muzzle velocity of the bullet? Answer in m/s

632

A two-stage rocket of mass m is traveling at a speed of 6.0 E3 m/s relative to the earth when a pre-designed explosion separates the rocket into two sections of equal mass. After the explosion, one section moves away from the Earth at 2.0 E3 m/s faster than the other section. What is the speed of the faster section after the explosion, in m/s?

7.0 E3

In the figure below, a crate is being pulled across a horizontal floor with a force F=10.0N at the angle fata =37 degrees as shown. The mass of the crate is m=1.0kg, and the coefficient of kinetic friction between the crate and the floor is u=0.20. Find the acceleration of the cart, in m/s2

7.2

an automobile traveling at 95.0km/h overtakes a 1.2 km long train traveling in the same direction on a track parallel to the road. If the trian's speed is 80 km/h, how far will the car have traveled in the time it takes to pass the train? answer in km.

7.6

what linear speed (in km/s) must an Earth satellite have to be in a circular orbit at an altitude of 160km above the earth's surface?

7.82

An object initially at rest at position X=0 starts moving with a constant acceleration. After 1 sec, the object is located at x=2m. What is the object's velocity at t=2 sec? Answer in m/s

8

A 70.0-kg crate, starting from rest, is pulled across a floor with a constant horizontal force of 240.0 N. For the first 10.0m the floor is frictionless and for the next 10.0m the coefficient of friction is 0.300. What is the final speed of the crate?

8.85

A passenger dangles her watch from a thin piece of string while the jetliner she takes off from the airport. The string makes a 25 degree angle relative to the vertical as the aircraft accelerates for takeoff, which takes 18 seconds. Find the takeoff speed of the aircraft, in m/s. Use g=10N/kg

84

An object of mass 2 kg has a linear momentum of magnitude 6 kg m/s. What is the object's kinetic energy, in joules?

9

Suppose a binary star system consists of two stars of equal mass. They are observed to be separated by 8.0 E7 km and take 12.6 earth years to orbit about a point midway between them. What is the mass of each? Answer in kg.

9.6E26

A relatively dense, relatively aerodynamic rocket moves vertically upward, starting from rest with an acceleration of 30 m/s for 4 s. It runs out of fuel at the end of the 4s, but continues to ascend vertically upward. What altitude (height) does the rocket reach above the level ground below? Answer in meters. Use g=-10m/s

960

Which statement below is correct about gravitational phenomena as discussed in class

All of choices A-D are correct

when babe ruth hit a homer over the 11 meter high right field fence 80 m from home plate, approximately what was the minimum speed of the ball when it left the bat? assume the ball was hit 1.0 m above the ground and its path initially made a 37 degree angle with the level ground. Answer in m/s.

B

A student is asked to determine the mass of Jupiter. Knowing which of the following about Jupiter and one of its moons will allow the determination to be made? A) The time it takes for Jupiter to orbit the sun B) The time it takes for the moon to orbit Jupiter C) The average distance between the moon and Jupiter

B and C

Here are three pairs of initial and final positions, respectively, along the X axis. What pairs give a negative displacement?

B and C

According to your textbook, what is the reason gravity plays the dominant role in the universe?

Because it is only attractive in nature

This question refers to the friction lab we did, in which we could the coefficient of friction for 3 different situations. In that lab, why did the force reading on the spring equal the force of friction?

Because the forces must be equal in magnitude when the velocity of the pull is constant

According to Einstein, why do the planets in our solar system follow a curved rather than straight path through space?

Because the sun curves space time in the vicinity of the planets

What is meant be the term "uniform acceleration"?

C and D

Refer to the figure below for this problem. In 3 situations, a briefly applied horizontal force changes the velocity of a hockey puck that slides over frictionless ice. The overhead views indicate, for each situation, the pucks initial speed is vi, and its final speed, vf, and the direction of the corresponding velocity vectors. Rank the situations according to the work done on the puck by the applied force, most positive first and most negative last.

C, B, A

A car moves in a circular path. What specific force provides the centripetal force on the wheels of the car?

Friction Force

On a "rotor-ride" at a carnival, people are rotated in a vertical cylinder. The floor drops out, and the riders are "stuck" against the walls of the cylinder. Which of the following variables does not affect whether or not a person stays stuck against the wall?

Mass of the rider

Two skaters are initially at rest next to each other on frictionless ice. Skater A pushes on skater B. If skater A has greater mass than skater B, which of the following correctly relates the magnitudes of their momentums, p, and their kinetic energies, K, after the push?

Pa=Pb and Ka<Kb

What was the famous verification of Einstein's General Theory of Relativity discussed in your text book?

The correct prediction of the bending of light around the sun.

A particle moves along an x-axis. If the particle's velocity changes from -2.0m/s to 2.0m/s, choose the best answer that describes the kinetic energy of the particle and the work done on the particle.

The kinetic energy of the particle remains the same; the work done on the particle is zero.

Two objects are thrown from the top of a tall building. One is thrown up and the other is thrown down, both of them with the same initial speed. What are their speeds just before they hit the street?

They are traveling at the same speed

In the figure below, a projectile following a standard projectile trajectory is thrown up past the windows shown. Windows 4, 5, and 6 are identical in size and equality spaced horizontally. Rank those three windows according to the time the projectile takes to pass them, greatest (largest value of time) first.

all tie for the same value

A person throws a marble straight up into the air, releasing it a short height above the ground and catching it at that same height. If air resistance is negligible, which of the following graphs of position y versus time t is correct for the motion of the marble as it goes up and then comes down?

b.)

which equation below would you use to solve a problem in which you are given the initial and final velocity, and the acceleration, and are asked to find x?

b.) vf2=vi2+2ax

A pilot drops a bomb from a plane flying horizontally. The pilot continues flying horizontally at the same speed after the bomb is released. Neglecting air resistance, when the bomb hits the ground, the horizontal position of the plane will

be directly over the bomb

Refer to the figure below for this question. At which of the numbered points does the particle reverse its direction of travel?

c.) 3, 5

A racing car is moving around the circular track of radius 300 meters shown above. At the instant when the car's velocity is directed due east, its acceleration is directed due south and has a magnitude of 3 meters per second squared. When viewed from above, the car is moving

clockwise at 30m/s

If the object is thrown vertically upward, the direction and magnitude of its acceleration while it is in the air is

downward and constant

Shown in figure 2.6 are five pairs of velocity and position functions. How many pairs are qualitatively consistent with each other?

four

What is the primary topic that is explained in Einstein's General Theory of Relativity?

gravity

A person standing on a horizontal floor is acted on by two forces: the downward pull of gravity and the upward supporting force from the solid concrete floor. These two forces

have equal magnitudes but do not form an action/reaction pair

A block of mass 10kg is at rest on an incline of 30 degrees to the horizontal. Which one of the statements below is the most correct about the magnitude of the force of friction that acts on the mass?

it is equal to the component of the force of gravity parallel to the plane

A block of mass m slides from rest down an inclined plane of length s and height h. If F is the magnitude of the force of kinetic friction acting on the block as it slides, then the kinetic energy of the block when it reaches the bottom of the incline will be equal to

mgh - Fs

a cannonball is shot toward a castle wall at an initial speed of 100m/s at an angle of 37 degrees above the horizontal. The castle wall is 160m away and 80 m tall. When (time, in sec) will the velocity vector of the cannonball point at 45 degrees below the horizontal (assume ground level)?

never

A=20m [53 degrees N of W]; B=10m [37 degrees S of W] C=15m [E]. If D=-A-3B-2C, what is the magnitude of D

square root of 40

Two objects move toward each other, collide, and separate. If there was no net external force acting on the objects, but some kinetic energy was lost, then

the collision was not elastic and total linear momentum was conserved

The area "under the curve" on a velocity-time graph is equal to

the displacement of the object

A 3.0-kg object moves to the right with a speed of 4.0m/s. It collides head-on with a 6.0-kg object moving to the left at a speed of 2.0m/s. Which statement below is correct about the situation?

the total momentum of the system both before and after the collision is zero.

which statement below is most correct about the acceleration lab?

the v-t graph slope showed that the velocity of the car increased as it traveled down the ramp

An object moves in a circular path at a constant speed. Consider the direction of the object's velocity and acceleration vectors

the vectors are perpindicular

A car goes around a curve with a radius r at a constant speed v. What is the direction on the net force of the car?

toward the curve's center

What does the slope of a line on a position-time graph represent?

velocity

For this problem, use Graph # 1. What is the approximate instantaneous velocity, in m/s, of the object at t=6.9 sec.

zero

The coefficient of static and kinetic frictions between a 3.0-kg box and a desk are 0.40 and 0.30, respectively. What is the net force on the box when a 10.0-N horizontal force is applied to the box? Answer in Newtons.

zero