Question 1

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

Accepted Answer

A) first 
B) second 
C) third 
D) fourth 
A) first 
B) second 
C) third 
D) fourth

Question 2

​The figure shows a block on an inclined plane.  
What is the expression for the normal force acting on the block?

Accepted Answer

A) ​Mg 
B) ​Mgcosθ 
C) ​Mgsinθ 
D) ​Mgtanθ 
A) ​Mg 
B) ​Mgcosθ 
C) ​Mgsinθ 
D) ​Mgtanθ

Question 3

A 60.0-kg man jumps 1.70 m down onto a concrete walkway.His downward motion stops in 0.025 seconds.If he forgets to bend his knees,what force is transmitted to his leg bones?

Accepted Answer

A) 13 900 N 
B) 346 N 
C) 8 000 N 
D) 1 790 N 
A) 13 900 N 
B) 346 N 
C) 8 000 N 
D) 1 790 N

Question 4

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:

Accepted Answer

A) Carlos will stop. 
B) Carlos will slow down. 
C) Carlos will continue down at a constant velocity. 
D) the rope must break. 
A) Carlos will stop. 
B) Carlos will slow down. 
C) Carlos will continue down at a constant velocity. 
D) the rope must break.

Question 5

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?

Accepted Answer

A) 37.5 N 
B) 150 N 
C) 225 N 
D) 75.0 N 
E) 0 N 
A) 37.5 N 
B) 150 N 
C) 225 N 
D) 75.0 N 
E) 0 N

Question 6

A cart of weight 15.0 N is accelerated across a level surface at 0.15 m/s2.What net force acts on the wagon? (g = 9.8 m/s2)

Accepted Answer

A) 22 N 
B) 0.23 N 
C) 2.3 N 
D) 10 N 
E) 100 N 
A) 22 N 
B) 0.23 N 
C) 2.3 N 
D) 10 N 
E) 100 N

Question 7

An automobile of mass 2 500 kg moving at 50.0 m/s is braked suddenly with a constant braking force of 8 500 N.How far does the car travel before stopping?

Accepted Answer

A) 7.35 m 
B) 368 m 
C) 184 m 
D) 551 m 
E) 19.2 m 
A) 7.35 m 
B) 368 m 
C) 184 m 
D) 551 m 
E) 19.2 m

Question 8

Two blocks of masses 30.0 kg and 8.0 kg are connected together by a light string and rest on a frictionless level surface.Attached to the 8.0-kg mass is another light string,which a person uses to pull both blocks horizontally.If the two-block system accelerates at 0.60 m/s2 what is the tension in the connecting string between the blocks?

Accepted Answer

A) 23 N 
B) 37 N 
C) 18 N 
D) 4.8 N 
E) 50 N 
A) 23 N 
B) 37 N 
C) 18 N 
D) 4.8 N 
E) 50 N

Question 9

A 12.0-kg mass is placed on a 29.0° incline and friction keeps it from sliding.The coefficient of static friction in this case is 0.660,and the coefficient of sliding friction is 0.546.The mass is given a shove causing it to slide down the incline.What is the frictional force while the mass is sliding?

Accepted Answer

A) 57.0 N 
B) 102.9 N 
C) 56.2 N 
D) 67.9 N 
E) ​10.5 N 
A) 57.0 N 
B) 102.9 N 
C) 56.2 N 
D) 67.9 N 
E) ​10.5 N

Question 10

A block is launched up an incline plane.After going up the plane,it slides back down to its starting position.The coefficient of friction between the block and the plane is 0.3.The time for the trip up the plane:

Accepted Answer

A) is the same as the time for the trip down. 
B) is more than the time for the trip down. 
C) is less than the time for the trip down. 
D) cannot be found without knowing the angle of inclination. 
A) is the same as the time for the trip down. 
B) is more than the time for the trip down. 
C) is less than the time for the trip down. 
D) cannot be found without knowing the angle of inclination.

Question 11

The three blocks in the figure are on a frictionless surface.If F = 48.0 N,m1 = 2.0 kg,m2 = 1.5 kg,and m3 = 3.5 kg,what is the tension in the cord?

Accepted Answer

A) 24.0 N 
B) 6.86 N 
C) 13.7 N 
D) 32.0 N 
A) 24.0 N 
B) 6.86 N 
C) 13.7 N 
D) 32.0 N

Question 12

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)

Accepted Answer

A) 0.40 
B) 0.50 
C) 0.30 
D) 0.20 
E) 2.8 
A) 0.40 
B) 0.50 
C) 0.30 
D) 0.20 
E) 2.8

Question 13

What condition must apply to a system's state of motion for it to be regarded as an inertial frame of reference?

Accepted Answer

A) in decreasing velocity 
B) in constant velocity 
C) in constant acceleration 
D) in increasing acceleration 
A) in decreasing velocity 
B) in constant velocity 
C) in constant acceleration 
D) in increasing acceleration

Question 14

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?

Accepted Answer

A) 9.1E+2 N 
B) 5.4E+2 N 
C) 700 N 
D) 1.4E+3 N 
E) 9.6E+2 N 
A) 9.1E+2 N 
B) 5.4E+2 N 
C) 700 N 
D) 1.4E+3 N 
E) 9.6E+2 N

Question 15

The coefficient of static friction between the tires of a car and the street is μs = 0.70.Of the following,what is the steepest inclination angle of a street on which a car can be parked (with wheels locked)without slipping?

Accepted Answer

A) 30° 
B) 40° 
C) 35° 
D) 45° 
E) ​32° 
A) 30° 
B) 40° 
C) 35° 
D) 45° 
E) ​32°

Question 16

A man of weight W​man is standing on the second floor and is pulling on a rope to lift a box of weight W​box from the floor below.The rope,which is of negligible weight,has tension T in it,but the pull of the rope is insufficient to lift the box off the floor.What is the magnitude of the normal force that the second floor exerts on the man in this situation?

Accepted Answer

A) W​man 
B) W​man + T 
C) W​man + T + a nonzero portion of W​box 
D) W​man + T + W​box 
A) W​man 
B) W​man + T 
C) W​man + T + a nonzero portion of W​box 
D) W​man + T + W​box

Question 17

A boxcar of mass 125 tons at rest becomes uncoupled on a 2.0° grade.If the track is considered to be frictionless,what speed does the boxcar have after 9.0 seconds?

Accepted Answer

A) 4.0 m/s 
B) 0.038 m/s 
C) 31 m/s 
D) 3.1 m/s 
E) 0.31 m/s 
A) 4.0 m/s 
B) 0.038 m/s 
C) 31 m/s 
D) 3.1 m/s 
E) 0.31 m/s

Question 18

A sled weighs 325 N.It is held in place on a frictionless 30.0° slope by a rope attached to a stake at the top;the rope is parallel to the slope.Find the tension in the rope.

Accepted Answer

A) 281 N 
B) 650 N 
C) 375 N 
D) 163 N 
E) 188 N 
A) 281 N 
B) 650 N 
C) 375 N 
D) 163 N 
E) 188 N

Question 19

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:

Accepted Answer

A) the weight of the car times the coefficient of kinetic friction. 
B) the normal force of the road times the coefficient of kinetic friction. 
C) the normal force of the road times the coefficient of static friction. 
D) zero. 
A) the weight of the car times the coefficient of kinetic friction. 
B) the normal force of the road times the coefficient of kinetic friction. 
C) the normal force of the road times the coefficient of static friction. 
D) zero.

Question 20

A trapeze artist,with swing,weighs 800 N;he is momentarily held to one side by his partner so that the swing ropes make an angle of 25.0° with the vertical.In such a condition of static equilibrium,what is the horizontal force being applied by the partner?

Accepted Answer

A) 338 N 
B) 693 N 
C) 400 N 
D) 373 N 
E) 572 N 
A) 338 N 
B) 693 N 
C) 400 N 
D) 373 N 
E) 572 N

Exam 4: Newtons Laws of Motion

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

​The figure shows a block on an inclined plane. What is the expression for the normal force acting on the block?

A 60.0-kg man jumps 1.70 m down onto a concrete walkway.His downward motion stops in 0.025 seconds.If he forgets to bend his knees,what force is transmitted to his leg bones?

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:

A cart of weight 15.0 N is accelerated across a level surface at 0.15 m/s2.What net force acts on the wagon? (g = 9.8 m/s2)

An automobile of mass 2 500 kg moving at 50.0 m/s is braked suddenly with a constant braking force of 8 500 N.How far does the car travel before stopping?

A block is launched up an incline plane.After going up the plane,it slides back down to its starting position.The coefficient of friction between the block and the plane is 0.3.The time for the trip up the plane:

The three blocks in the figure are on a frictionless surface.If F = 48.0 N,m1 = 2.0 kg,m2 = 1.5 kg,and m3 = 3.5 kg,what is the tension in the cord?

What condition must apply to a system's state of motion for it to be regarded as an inertial frame of reference?

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?

The coefficient of static friction between the tires of a car and the street is μs = 0.70.Of the following,what is the steepest inclination angle of a street on which a car can be parked (with wheels locked)without slipping?

A boxcar of mass 125 tons at rest becomes uncoupled on a 2.0° grade.If the track is considered to be frictionless,what speed does the boxcar have after 9.0 seconds?

A sled weighs 325 N.It is held in place on a frictionless 30.0° slope by a rope attached to a stake at the top;the rope is parallel to the slope.Find the tension in the rope.

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:

A trapeze artist,with swing,weighs 800 N;he is momentarily held to one side by his partner so that the swing ropes make an angle of 25.0° with the vertical.In such a condition of static equilibrium,what is the horizontal force being applied by the partner?

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Filters

The figure shows a block on an inclined plane. What is the expression for the normal force acting on the block?

A cart of weight 15.0 N is accelerated across a level surface at 0.15 m/s².What net force acts on the wagon? (g = 9.8 m/s²)

The three blocks in the figure are on a frictionless surface.If F = 48.0 N,m₁ = 2.0 kg,m₂ = 1.5 kg,and m₃ = 3.5 kg,what is the tension in the cord?

The coefficient of static friction between the tires of a car and the street is μ_s = 0.70.Of the following,what is the steepest inclination angle of a street on which a car can be parked (with wheels locked)without slipping?