Physics test 1

36 N

A 14-kg block rests on a level frictionless surface and is attached by a light string to a 5.0-kg hanging mass where the string passes over a massless frictionless pulley. If g = 9.8 m/s2, what is the tension in the connecting string?

0.30

A 150-kg crate is placed on an adjustable inclined plane. As one end of the incline is raised, the crate begins to move downward. If the crate slides down the plane with an acceleration of 0.20 m/s2 when the incline angle is 18°, what is the coefficient of kinetic friction between ramp and crate? (g = 9.8 m/s2)

-0.47 m/s2

A 16-kg mass is placed on a 25° incline and friction keeps it from sliding. The coefficient of static friction in this case is 0.574 and the coefficient of sliding friction is 0.519. The mass is given a shove causing it to slide down the incline. Taking down the incline as positive, what is the acceleration of the mass while it is sliding?

7.38 m/s2

A 16.0-kg mass and a 2.25-kg mass are connected by a light string over a massless, frictionless pulley. If g = 9.8 m/s2, what is the acceleration of the system when released?

17° N of E

A 2 000-kg sailboat experiences an eastward force of 4 500 N by the ocean tide and a wind force against its sails with magnitude of 1 500 N directed toward the northwest (45° N of W). What is the direction of the resultant acceleration?

0.32

A 200-kg box is placed on a ramp. As one end of the ramp is raised, the box begins to move downward just as the angle of inclination reaches 18.0°. What is the coefficient of static friction between box and ramp?

7.5E+3 N

A 4 500-N weight is suspended in equilibrium by two cables. Cable 1 applies a horizontal force to the right of the object and has a tension, T1. Cable 2 applies a force upward and to the left at an angle of 37.0° to the negative x-axis and has a tension, T2. Find T2.

6.6E+3 N

A 5 500-N weight is held suspended in equilibrium by two cables. Cable 1 applies a horizontal force to the right of the object and has a tension, T1. Cable 2 applies a force upward and to the left at an angle of 40.0° to the negative x-axis and has a tension, T2. What is the tension, T1?

8.0°

A 500-N tightrope walker stands at the center of the rope. If the rope can withstand a tension of 1 800 N without breaking, what is the minimum angle the rope can make with the horizontal?

3.47 m/s2

A European sports car dealer claims that his car will accelerate at a constant rate from rest to 100 km/h in 8.00 s. If so, what is the acceleration? (Hint: First convert speed to m/s.)

0.64 m

A ball is rolled horizontally off a table with an initial speed of 0.24 m/s. A stopwatch measures the ball's trajectory time from table to the floor to be 0.36 s. What is the height of the table? (g = 9.8 m/s2 and air resistance is negligible)

> 0.5 T

A ball rolls down an incline, starting from rest. If the total time it takes to reach the end of the incline is T, how much time has elapsed when it is halfway down the incline?

390 N

A barefoot field-goal kicker imparts a speed of 30 m/s to a football at rest. If the football has a mass of 0.45 kg and time of contact with the football is 0.035 s, what is the force exerted on the foot?

631 N

A baseball batter hits an incoming 45.0-m/s fastball. The ball leaves the bat at 56.0 m/s after a ball-on-bat contact time of 0.040 s. What is the force exerted on the 0.25-kg baseball?

1.68 × 102 m

A baseball is released at rest from the top of the Washington Monument. It hits the ground after falling for 5.85 s. What was the height from which the ball was dropped? (g = 9.80 m/s2 and assume air resistance is negligible)

at the top of the trajectory

A baseball is thrown by the center fielder (from shoulder level) to home plate where it is caught (on the fly at an equal shoulder level) by the catcher. At what point is the ball's speed at a minimum? (air resistance is negligible)

at the top of the trajectory

A baseball is thrown by the center fielder (from shoulder level) to home plate where it is caught (on the fly at shoulder level) by the catcher. At what point does the magnitude of the vertical component of velocity have its minimum value? (air resistance is negligible)

acceleration is constant during entire trajectory

A baseball is thrown by the center fielder (from shoulder level) to home plate where it is caught (on the fly at shoulder level) by the catcher. At what point is the magnitude of the acceleration at a minimum? (air resistance is negligible)

7.77 m/s

A baseball player throws a ball straight up into the air. At a height of 3.00 m above the release point, the ball is moving at 1.25 m/s. What was the ball's initial speed?

10.8 m

A baseball thrown from the outfield is released from shoulder height at an initial velocity of 29.1 m/s at an initial angle of 30.0° with respect to the horizontal. What is the maximum vertical displacement that the ball reaches during its trajectory?

5.6 m/s

A basketball player can jump 1.6 m off the hardwood floor. With what upward velocity did he leave the floor?

0.35 m/s2

A bird, accelerating from rest at a constant rate, experiences a displacement of 25 m in 12 s. What is its acceleration?

20 N

A block of mass 4.0 kg rests on a horizontal surface where the coefficient of kinetic friction between the two is 0.20. A string attached to the block is pulled horizontally, resulting in a 3.0-m/s2 acceleration by the block. Find the tension in the string. (g = 9.80 m/s2)

211 s

A boat moves at 10.8 m/s relative to the water. If the boat is in a river where the current is 2.00 m/s, how long does it take the boat to make a complete round trip of 1 100 m upstream followed by a 1 100-m trip downstream?

4 km/h

A boat travels upstream and after one hour has gone 10 km. The boat next travels downstream and after one hour has gone 18 km. If the boat's speed relative to the water is constant, what is the speed of the current in the river?

the one above the horizontal

A box is to be moved across a level surface. A force of magnitude 200 N may be applied at an angle of 30° below the horizontal to push the box or at an angle of 30° above the horizontal to pull the box, either application sufficient to overcome friction and move the box. Which application will cause the box to have the greater acceleration?

mg sin θ.

A box of mass m is placed on an incline with angle of inclination θ. The box does not slide. The magnitude of the frictional force in this case is:

μs = tanθ

A box slides up an incline with an angle of elevation θ. When the box reaches its maximum distance up the incline it stops and does not slide down the incline due to friction. What is the minimum value of the coefficient of static friction for this to occur?

-7.1 + 5.7

A car is initially traveling west at 25 mph, and makes a turn north. As the car finishes the turn, its velocity is 20 mph north. It takes 3.5 seconds to complete the turn. What is the average acceleration of the car while it is turning, in mph/s? Let east be the positive-x direction and north be the positive-y direction

186 km/h/h

A car's initial velocity is 50.0 km/h in the direction 60.0° north of east, and its final velocity is 70.0 km/h in the direction 40.0° south of east. If the time period for this journey is 30.0 minutes, what is the magnitude of the car's average acceleration?

55 m

A cart is given an initial velocity of 5.0 m/s and experiences a constant acceleration of 2.4 m/s2. What is the magnitude of the cart's displacement during the first 5.0 s of its motion?

72.0 ft^3/min

A cement truck can pour 160 cubic yards of cement per hour. Express this in ft3/min.

7.6E-2 cubic feet

A cereal box has the dimensions of 0.14 m × 0.22 m × 0.070 m. If there are 3.28 feet per meter, then what is the volume of the box in cubic feet?

79 m

A cheetah can maintain its maximum speed of 96.0 km/hr for 26.0 seconds. What minimum distance must a gazelle running 85.0 km/hr be ahead of the cheetah to escape?

27.3 m

A fireman, 57.6 m away from a burning building, directs a stream of water from a fire hose at an angle of 35.2° above the horizontal. If the initial speed of the stream is 42.7 m/s, at what height will the stream of water strike the building?

3.30E+4 furlongs/fortnight

A furlong is a distance of 220 yards. A fortnight is a time period of two weeks. A race horse is running at a speed of 6.00 yards per second. What is his speed in furlongs per fortnight?

250 N

A girl is using a rope to pull a box that weighs 300 N across a level surface with constant velocity. The rope makes an angle of 30° above the horizontal, and the tension in the rope is 100 N. What is the normal force of the floor on the box?

74 m/s

A helicopter is traveling at 50.0 m/s at a constant altitude of 150 m over a level field. If a wheel falls off the helicopter, with what speed will it hit the ground? (g = 9.8 m/s2 and air resistance negligible)

43 m

A high fountain of water is in the center of a circular pool of water. You walk the circumference of the pool and measure it to be 190 meters. You then stand at the edge of the pool and use a protractor to gauge the angle of elevation of the top of the fountain. It is 55°. How high is the fountain?

None of the answers is correct.

A hiker walks 200 m west and then walks 100 m north. In what direction is her resulting displacement?

μ = 0.031

A hockey puck moving at 7.00 m/s coasts to a halt in 80.0 m on a smooth ice surface. What is the coefficient of friction between the ice and the puck?

0.78 m/s2

A horizontal force of 675 N is needed to overcome the force of static friction between a level floor and a 300-kg crate. What is the acceleration of the crate if the 675-N force is maintained after the crate begins to move and the coefficient of kinetic friction is 0.15?

0.248

A horizontal force of 850 N is needed to overcome the force of static friction between a level floor and a 350-kg crate. If g = 9.8 m/s2, what is the coefficient of static friction?

120 m, 188 m

A jogger runs halfway around a circular path with a radius of 60.0 m. What, respectively, are the magnitude of the displacement and the distance jogged?

48 N

A man pulls a sled at a constant velocity across a horizontal snow surface. If a force of 85 N is being applied to the sled rope at an angle of 56° to the ground, what is the force of friction between sled and snow?

1 420

A marble has a radius of 16 mm. Approximately how many marbles will fit in a cube-shaped container with each side equal to 36 cm?

1.03E+3 m

A parachutist jumps out of an airplane and accelerates with gravity to a maximum velocity of 68.6 m/s in 7.00 seconds. She then pulls the parachute cord and after a 4.00-second constant deceleration, descends at 10.5 m/s for 60.0 seconds, reaching the ground. From what height did the parachutist jump?

The train is slowing down.

A physics student is riding on a train traveling north. Having read about inertia, the student performs an experiment with a golf ball. He reaches over the aisle and drops the ball from rest. Instead of hitting the floor directly below the student's hand, it hits to the north, i.e., forward of that position. Which of the following might be the cause for this to happen?

209 mph

A plane is moving due north, directly towards its destination. Its airspeed is 210 mph. A constant breeze is blowing from west to east at 20.0 mph. At what rate is the plane moving north?

6.79° W of N

A plane is moving due north, directly towards its destination. Its airspeed is 210 mph. A constant breeze is blowing from west to east at 25.0 mph. In which direction is the plane pointed?

more than one hour

A plane is moving due north, directly towards its destination. Its airspeed is 220 mph. A constant breeze is blowing from west to east at 50 mph. How long will it take for the plane to travel 220 miles north?

49.4 m/s, downward

A projectile is fired directly upwards at 49.4 m/s. A second projectile is dropped from rest at some higher elevation at the instant the first projectile is fired and passes the first projectile 3.00 s later. From the frame of reference of the first projectile, what is the velocity of the second projectile as it passes by?

39 yards

A quarterback takes the ball from the line of scrimmage, runs backward for 12 yards, then sideways parallel to the line of scrimmage for 18 yards. He then throws a 47-yard forward pass straight downfield perpendicular to the line of scrimmage. The receiver is tackled immediately. How far is the football displaced from its original position?

78.8 m/s

A railroad train travels forward along a straight track at 90.0 m/s for 1 000 m and then travels at 70.0 m/s for the next 1 000 m. What is the average velocity?

228 ± 4

A rectangular-shaped patio has a base length equal to (24.5 ± 0.2) m and a height equal to (9.3 ± 0.1) m. What is the area of the patio, including its uncertainty?

2.1 m/s2

A rock is rolled in the sand. It starts at 5.0 m/s, moves in a straight line for a distance of 6.0 m, and then stops. What is the magnitude of the average acceleration?

48 m

A rock is thrown straight down with an initial velocity of 14.3 m/s from a cliff. What is the rock's displacement after 2.0 s? (Acceleration due to gravity is 9.80 m/s2.)

31.9 m

A rock is thrown straight up with an initial velocity of 25.0 m/s. What maximum height will the rock reach before starting to fall downward? (Take acceleration due to gravity as 9.80 m/s2.)

34 m/s

A rock, released at rest from the top of a tower, hits the ground after 3.5 s. What is the speed of the rock as it hits the ground? (g = 9.8 m/s2 and air resistance is negligible)

161 N

A shot-putter moves his arm and the 6.00-kg shot through a distance of 1.25 m, giving the shot a velocity of 8.20 m/s from rest. Find the average force exerted on the shot during this time.

145 N

A sled weighs 160 N. It is held in place on a frictionless 25.0° slope by a rope attached to a stake at the top; the rope is parallel to the slope. What is the normal force of the slope acting on the sled?

12.4 m/s

A startled deer runs 520 m at 20.0° north of east for half a minute, then turns and runs 380 m at 55.0° north of west for 15.0 seconds and stops. What is the average velocity of the deer during this time?

26.1 m

A stone is thrown with an initial speed of 11.5 m/s at an angle of 50.0 above the horizontal from the top of a 30.0-m-tall building. Assume air resistance is negligible, and g = 9.8 m/s20. What is the magnitude of the horizontal displacement of the rock?

115 m

A string attached to an airborne kite is maintained at an angle of 44.0° with the horizontal. If a total of 160 m of string is reeled in while bringing the kite back to the ground, what is the horizontal displacement of the kite in the process? (Assume the kite string doesn't sag.)

the acceleration of the car

A strobe photograph shows equally-spaced images of a car moving along a straight road. If the time intervals between images is constant, which of the following cannot be positive?

200

A student adds two vectors with magnitudes of 200 and 70. Which one of the following is the only possible choice for the magnitude of their sum?

35.2

A surveyor stands 100 m from the base of a building, and uses a transit to determine that the angle of elevation to the building's roof is 19.0°. If the transit height is 0.80 m, what is the height of the building?

9.4 blocks

A taxicab moves five blocks due north, five blocks due east, and another three blocks due north. Assume all blocks are of equal size. How far is the taxi from its starting point?

the force of the stone on the glass = the force of the glass on the stone

A thrown stone hits a window, but doesn't break it. Instead it reverses direction and ends up on the ground below the window. In this case, we know:

9.1E+2 N

A trapeze artist, with swing, weighs 700 N; he is being held to one side by his partner so that the swing ropes make an angle of 40.0° with the vertical. In such a condition of static equilibrium, what is the tension in the rope?

8 cm

A triangle has sides of length 7 cm and 11 cm. If the triangle is a right triangle, which of the following could be the length of the third side, to the nearest centimeter?

the velocity of the ball is not changing.

A v vs. t graph is drawn for a ball moving in one direction. The graph starts at the origin and at t = 5 s the acceleration of the ball is zero. We know that at t = 5 s,

3 900

Calculate (0.83 + 0.049)(4.4 × 103), keeping only significant figures.

8.

Doubling the radius of a sphere results in increasing its volume by a factor of

1.1E+4 N

Find the tension in an elevator cable if the 1 500-kg elevator is descending with an acceleration of 2.8 m/s2, downward.

x = -2.0

For which of the values below is x > x7?

cosine

In a two-dimensional Cartesian coordinate system the y-component of a given vector is equal to that vector's magnitude multiplied by which trigonometric function, with respect to the angle between vector and y-axis?

dividing by cosine

In a two-dimensional Cartesian system, the x-component of a vector is known, and the angle between vector and x-axis is known. Which operation is used to calculate the magnitude of the vector? (taken with respect to the x-component)

It is positive.

In one-dimensional motion, the average speed of an object that moves from one place to another and then back to its original place has which of the following properties?

half-way through the time interval.

In the case of constant acceleration, the average velocity equals the instantaneous velocity:

Carlos will continue down at a constant velocity.

It is late and Carlos is sliding down a rope from his third-floor window to meet his friend Juan. As he slides down the rope faster and faster, he becomes frightened and grabs harder on the rope, increasing the tension in the rope. As soon as the upward tension in the rope becomes equal to his weight:

1.66 m/s2

Jamal pulls a 250-N sled up a 29.0° slope at constant speed by a force of 200 N. Near the top of the hill he releases the sled. With what acceleration does the sled go down the hill?

159m

John throws a baseball from the outfield from shoulder height, at an initial velocity of 41.5 m/s at an initial angle of 40.0° with respect to the horizontal. The ball is in its trajectory for a total interval of 5.00 s before the third baseman catches it at an equal shoulder-height level. (Assume air resistance negligible.) What is the ball's horizontal displacement?

5.84E+24

One mole of ammonia (NH3) has a mass of 17.0 g, and one mole is equal to 6.02 × 1023 molecules. How many hydrogen (H) atoms are in 55.0 g of ammonia? Note that each molecule of ammonia has 3 hydrogen atoms.

south of east.

Vector points north, and vector points east. If = − , then vector points

cm^2in.

Volume can be measured in units of m3. Which of the following unit combinations also result in volume?

68hrs

Water flows into a swimming pool at the rate of 7.0 gal/min. The pool is 17 ft wide, 32 ft long and 7.0 ft deep. How long does it take to fill? (1 U.S. gallon = 231 cubic inches)

1.78 s

At the top of a cliff 100 m high, Raoul throws a rock upward with velocity 15.0 m/s. How much later should he drop a second rock from rest so both rocks arrive simultaneously at the bottom of the cliff?

193 m

An automobile driver puts on the brakes and decelerates from 35.0 m/s to zero in 11.0 s. What distance does the car travel?

2.6E+4 N

An elevator weighing 20 000 N is supported by a steel cable. What is the tension in the cable when the elevator is being accelerated upward at a rate of 3.00 m/s2? (g = 9.80 m/s2)

6E+41

Approximately how many water molecules are in a lake with a volume of 12 100 km3? A water molecule measures approximately 2.75 × 10¯10 m in length.

L2, L3

Areas always have dimensions ____ while volumes always have dimensions ____.

51° N of E

Arvin the Ant travels 30 cm eastward, then 25 cm northward, and finally 10 cm westward. In what direction is Arvin now in with respect to his starting point?

less than the weight of the box.

As I pull a rope connected to a box at constant speed up a frictionless slope, pulling parallel to the slope, the tension in the rope will be:

less than the weight of the box.

As I slide a box at constant speed up a frictionless slope, pulling parallel to the slope, the tension in the rope will be:

bigger than his weight.

As a basketball player starts to jump for a rebound, he begins to move upward faster and faster until he leaves the floor. During this time that he is in contact with the floor, the force of the floor on his shoes is:

the normal force of the road times the coefficient of static friction.

As a car goes up a hill, there is a force of friction between the road and the tires rolling on the road. The maximum force of friction is equal to:

3

Assume when using a meter stick measuring can be done so that the last significant figure is in the tenth of a millimeter digit. If you are measuring an object with length between 6 and 7 cm, how many significant figures will result if you only use the part of the meter stick between the 1-cm and 9-cm positions?

3

Assume when using a meter stick measuring can be done so that the last significant figure is in the tenth of a millimeter digit. If you are measuring an object with length between 8 and 9 cm, how many significant figures will result if you only use the part of the meter stick between the 82-cm and 93-cm positions?

It would increase but be less than double.

Consider the sine of any angle between 30° and 40°. If the angle were doubled, what would happen to the sine of the angle?

5.58 m

Hector drives a pickup truck horizontally at 9.00 m/s. He is transporting a crate of delicate lead crystal. If the coefficient of static friction between the crate and the truck bed is 0.740, what is the minimum stopping distance for the truck so the crate will not slide?

One cannot tell with certainty when the number is written in the given form, but it will be one of the other given answers.

How many significant figures does the number 3 600 have?

16 cm.

Human reaction time is usually about 0.18 s. If your lab partner holds a ruler between your finger and thumb and releases it without warning, how far can you expect the ruler to fall before you catch it? The nearest value is

42°

I walk six miles in a straight line in a direction north of east, and I end up four miles north and several miles east. How many degrees north of east have I walked?

v = a/t

If a is acceleration, v is velocity, x is position, and t is time, then which equation is not dimensionally correct?

23 m

If point A is located at coordinates (-10, 7) and point B is located at coordinates (8, -8), what is the distance from A to B if the units of the coordinated system are meters?

time

If the displacement of an object, x, is related to velocity, v, according to the relation x = Av, the constant, A, has the dimension of which of the following?

the net force acting on the object is zero.

If we know an object is moving at constant velocity, we may assume:

being accelerated.

If we know that a nonzero net force is acting on an object, which of the following must we assume regarding the object's condition? The object is:

θ + φ = 90°

If θ and φ are each first quadrant angles, which of the following must be true if sin θ = cos φ?

1

If ϕ = 90° − θ, what is the value of sin2 ϕ + sin2 θ?

wavelength of light emitted by certain krypton atoms

In 1983 the standard meter was redefined to what it is currently. What was the previous definition from 1960 based on?

If x doubles, then y quadruples.

Note the expression: y = x2. Which statement is most consistent with this expression?

It could be any of the three.

Of vectors with lengths 5 m, 3 m, and 4 m, which has the greatest magnitude x component?

The curve will start at the zero of position and follow a straight line to its highest position at the later time.

On a velocity-time graph for a particle, suppose the plot starts at some positive velocity and then follows a straight line to zero at a later time. Which of the following must be true about a position vs. time graph for this same time interval?

5.4 feet

On planet Z, the standard unit of length is the foose. Ann the Astronaut is 5.2 feet tall on Earth. She lands on planet Z and is measured to be 88 foosi tall. Her partner Rachael is 92 foosi tall. How tall is Rachael on Earth?

29 N

Rita accelerates a 0.50-kg ball from rest to 8.0 m/s during the 0.14 s in which her foot is in contact with the ball. What average force does she apply to the ball during the kick?

characteristic frequency of the cesium-133 atom

Since 1967 the standard definition for the second has been based on which of the following?

The side opposite φ3.

Suppose the interior angles of a triangle are φ1, φ2, and φ3, with φ1 > φ2 > φ3. Which side of the triangle is the shortest?

14.4 N

There are nine books in a stack, each with a weight of 6 N. The coefficient of friction between all the books is 0.3 as is the coefficient between the table and the bottom book. What horizontal push must I just exceed on the next to bottom book to start sliding the top eight books off the bottom one?

(2.8 - 0.8 ) km

Terrence goes for a walk. He walks 2.0 km north, then turns and walks 4.0 km south of east. What is his displacement vector? Take east to be in the +-direction and north to be in the +-direction.

41.7 lb

The acceleration due to gravity on the Moon's surface is one-sixth that on Earth. An astronaut's life support backpack weighs 250 lb on Earth. What does it weigh on the Moon?

145 N

The acceleration due to gravity on the Moon's surface is one-sixth that on Earth. What net force would be required to accelerate a 25.0-kg object at 5.80 m/s2 on the Moon?

9.0E+4 cm^6

The basic function of an automobile's carburetor is to atomize the gasoline and mix it with air to promote rapid combustion. Assume that 30.0 cm3 of gasoline is atomized into N spherical droplets. Each droplet has a radius of 1.0 × 10−5 m. Find the total surface area of these N spherical droplets.

73 m/s

The coefficient of friction between a racecar's wheels and the track is 1.0. The car starts from rest and accelerates at a constant rate for 275 m. Find the maximum speed at the end of the race.

930

The distance from New York to London is 3 470 miles. If a plane takes 6.0 hours to fly this distance, what is the plane's average speed in kilometers per hour? 1 mile = 1.609 km.

2.8

Vector is 3.0 units in length and points along the positive x axis; vector is 5.0 units in length and points along a direction 150° from the positive x axis. What is the magnitude of the resulting vector when vectors and are added?

3.6E-3 in

The information on a one-gallon paint can is that the coverage, when properly applied, is 440 ft2. One gallon is 231 in3. What is the average thickness of the paint in such an application?

4.8E+57 atoms

The mass of a star is 8.0 × 1030 kg, and the mass of a hydrogen atom is 1.67 × 10−27 kg. If we assume that the star is mostly composed of hydrogen, approximately how many atoms are there in the star?

protons and neutrons.

The nuclei of atoms contain

2

The number 0.03 has how many significant figures?

10^15

The ratio T/m of the prefixes M and m has what value?

m/s.

The speed of a boat is often given in knots. If a speed of 5 knots were expressed in the SI system of units, the units would be:

third

The statement by Newton that "for every action there is an opposite but equal reaction" is regarded as which of his laws of motion?

rate of change of velocity

The value of an object's acceleration may be characterized in equivalent words by which of the following?

any of the above

Three forces, 14.0 N, 25.0 N, and 20.0 N, are acting on a 9.6-kg object. Which of the following forces could also be acting on the object if it is moving with constant velocity?

36 N

Three identical 6.0-kg cubes are placed on a horizontal frictionless surface in contact with one another. The cubes are lined up from left to right and a force is applied to the left side of the left cube causing all three cubes to accelerate to the right at 3.0 m/s2. What is the magnitude of the force exerted on the middle cube by the left cube in this case?

75.0 N

Two blocks are at rest on a horizontal frictionless surface with a compressed spring between them. The 15.0-kg block accelerates when the string holding the system in compression is cut and the 30.0-kg box accelerates in the opposite direction. What is the magnitude of the force from the expanding spring on the 30.0-kg box when the 15.0-kg box is undergoing an acceleration of 5.00 m/s2?

23 N

Two blocks of masses 20 kg and 9.0 kg are connected together by a light string and rest on a frictionless level surface. Attached to the 9.0-kg mass is another light string, which a person uses to pull both blocks horizontally. If the two-block system accelerates at 0.80 m/s2, what is the tension in the second string attached to the 9.0-kg mass?

17 N

Two blocks, joined by a string, have masses of 3.0 and 4.0 kg. They rest on a frictionless horizontal surface. A second string, attached only to the 4.0-kg block, has horizontal force = 40 N applied to it. Both blocks accelerate. Find the tension in the string between the blocks.

1.3 m/s2

Two ropes are attached to a 50-kg object. The first rope applies a force of 35 N and the second, 55 N. If the two ropes are perpendicular to each other, what is the resultant acceleration of the object?

56.3 km

Two ships set sail from the same port. Ship A sails a distance of 35.0 kilometers in a direction 30.0° north of east, and drops anchor. Ship B sails due south. When ship B is 30.0 km from the port, how far apart are the ships?

Vector 3

Vector 1 is 7 units long and is at 70°. Vector 2 is 5 units long and is at 155°. Vector 3 is 3 units long and is at 225°. Which vector has equal-magnitude components?

-4.2 + -2.7

Vector A is 2.0 + 3.5 . Vector B is -3.1 - 3.1 . What is A + 2B?

some value from 3 m to 7 m.

Vector is 2 m long, and vector is 5 m long. The length of the sum of the vectors must be

another displacement.

When we add a displacement vector to another displacement vector, the result is

at

Which formula is dimensionally consistent with an expression yielding a value for velocity? (a is acceleration, x is distance, and t is time)

electron

Which is smallest, an atom, a nucleus, a proton, or an electron?

fs ≤ μsn

Which is the correct expression for the force of static friction, where n is the normal force?

velocity

Which of the following is an example of a vector quantity?

all of the above

Which of the following is an example of the type of force that acts at a distance?

mass

Which of the following is not a vector quantity?

114

Which one of the choices below represents the preferred practice regarding significant figures when adding the following: 15.9 + 14 + 77.68 + 6.898?

200

Which one of the choices below represents the preferred practice regarding significant figures when multiplying the following: 15.0 × 5.6 × 2.33?

280 m

Wiley Coyote has missed the elusive road runner once again. This time, he leaves the edge of the cliff at 52.4 m/s horizontal velocity. If the canyon is 140 m deep, how far from his starting point at the edge of the cliff does the coyote land?