Question 1

A cricket batsman hits a ball with a bat. If the force with which the bat hits the ball is considered the action force, what is the reaction force?

Accepted Answer

A)  the force the bat exerts on the batsman's hands 
B)  the force on the ball exerted by the hand of the person who catches it 
C)  the force the ball exerts on the bat 
D)  the force the bowler exerts on the ball in throwing it 
E)  friction as the ball rolls to a stop

Question 2

Which of the following statements includes all the essential elements of Newton's first law?

Accepted Answer

A)  A body at rest persists in its state of rest unless acted on by a non-zero net external force. 
B)  A body persists in its state of rest or of uniform motion in a straight line as long as the net external force remains constant. 
C)  For every action there is an equal and opposite reaction. 
D)  A body persists in its state of rest or of uniform motion in a straight line unless acted on by a non-zero net external force. 
E)  The acceleration of a body is proportional to the net external force acting on it and to the mass of the body.

Question 3

Three forces,  ,  , and  , act on a mass of 4.2 kg. The forces are 
 = 2.0 N acting to the east, 
 = 5.0 N acting 45º to the north of east, and 
 = 4.0 N acting 30º to the north of west.
The magnitude of the net acceleration of the mass is

Accepted Answer

A)  2.9 m/s2  
B)  5.3 m/s2  
C)  1.4 m/s2  
D)  0.0 m/s2  
E)  18 m/s2

Question 4

Which of the following is a unit of force?

Accepted Answer

A)  m2/s2  
B)  kg · s2/m 
C)  kg · m/s2  
D)  N · s 
E)  N/kg

Question 5

A body of weight w is in free fall near the surface of Earth. What force does the body exert on the Earth?

Accepted Answer

A)  w 
B)  greater than w 
C)  less than w 
D)  9.81w 
E)  zero

Question 6

The weight of an object is

Accepted Answer

A)  the same as the mass of the object. 
B)  the quantity of matter in the object. 
C)  the mass of the object multiplied by the acceleration due to gravity at sea level, regardless of where the object is located. 
D)  the result of the gravitational force acting on the object. 
E)  the reading on a spring scale attached to the object.

Question 7

A mass m is traveling at an initial speed v0 = 25.0 m/s. It is brought to rest in a distance of 62.5 m by a force of 15.0 N. The mass is

Accepted Answer

A)  37.5 kg 
B)  3.00 kg 
C)  1.50 kg 
D)  6.00 kg 
E)  3.75 kg

Question 8

An astronaut lands on an Earthlike planet and drops a small lead ball with a mass of 76.5 g from the top of her spaceship. The point of release is 18 m above the surface of the planet and the ball takes 2.5 s to reach the ground. The astronaut's mass on Earth is 68.5 kg. Her weight on the planet is

Accepted Answer

A)  69.0 N 
B)  395 N 
C)  670 N 
D)  990 N 
E)  1.02 kN

Question 9

Three blocks are connected by massless cords and hung by a third massless cord to a beam. Mass m1 = 2 m2 = 3 m3. Mass m1 is the lowest block and m3 is the highest. The tension in the cord between the two highest blocks is

Accepted Answer

A)  3m1 $\times$ g/2 
B)  m1 $\times$ g/2 
C)  m1 $\times$ g/6 
D)  2m1 $\times$ g/3 
E)  6m1 $\times$ g/11

Question 10

A particle has a mass of 6.0 $\times$10-6 kg and a velocity of 800 m/s along the x axis when a force of 14.4 $\times$ 10-5 N along the y axis acts on the particle at right angles to its velocity. The acceleration of the particle is

Accepted Answer

A)  24 m/s2 along the x axis. 
B)  zero. 
C)  impossible to determine; forces never act at right angles to velocities. 
D)  24 m/s2 along the y axis. 
E)  tangential.

Question 11

A ball of mass 2.0 kg is acted on by two forces,  and  . At t = 0 s, the particle is at rest at the origin. The velocity vector at t = 2 s is

Accepted Answer

A)   
B)   
C)   
D)   
E)

Question 12

A bell hangs from a blue rope. A red rope attached to the side of the bell is pulled in the horizontal direction. This causes the blue rope to make an angle less than 90º with the vertical. Which of the following statements is true?

Accepted Answer

A)  The red rope is under greater tension than the blue rope. 
B)  The red rope is under the same tension as the blue rope. 
C)  The blue rope is under greater tension than the red rope. 
D)  The tensions cannot be compared unless the mass of the bell is known. 
E)  The tensions cannot be compared unless the angle that the blue rope makes with the vertical is known.

Question 13

A lamp of mass m hangs from a spring scale which is attached to the ceiling of an elevator. When the elevator is stopped at the fortieth floor, the scale reads mg. What does it read as the elevator slows down to stop at the ground floor?

Accepted Answer

A)  more than mg 
B)  less than mg 
C)  mg 
D)  zero 
E)  One cannot tell without knowing how fast the elevator is stopping.

Question 14

The figure below shows two forces, FS1U1B11S1U1B0 and FS1U1B12S1U1B0, acting on an object.  Use the vector diagrams to answer the next questions. 
-Which force vector best represents the resultant force on the object?

Accepted Answer

A)  (1) 
B)  (2) 
C)  (3) 
D)  (4) 
E)  none of the vectors

Question 15

A net force is exerted on an object toward the north. The object

Accepted Answer

A)  is moving toward the north. 
B)  is moving toward the east. 
C)  is moving toward the west. 
D)  is moving toward the south. 
E)  may be moving in any direction.

Question 16

If a force F is required to extend a spring a distance 5y, how far will it be extended by force 3F?

Accepted Answer

A)  5y 
B)  (3/5)y 
C)  (5/3)y 
D)  15y 
E)  (3/8)y

Question 17

Two masses m1 and m2 (with m2 > m1) are connected by a massless rope hung over a frictionless light pulley. If the masses are released then the acceleration of m2 in the downward direction is given by

Accepted Answer

A)  (m2 - m1) $\times$ g/(m1 - m2) 
B)  (m2 - m1) $\times$ g/(m1 + m2) 
C)  (m1 + m2) $\times$ g/(m2 - m1) 
D)  m2 $\times$ g/(m1 + m2) 
E)  g

Question 18

A boy holds a bird in his hand. The reaction force to the normal force exerted on the bird by the boy's hand is the force of:

Accepted Answer

A)  the Earth on the bird. 
B)  the bird on the Earth. 
C)  the hand on the bird. 
D)  the bird on the hand. 
E)  the Earth on the hand.

Question 19

A frictionless pulley of negligible mass is hung from the ceiling using a rope, also of negligible mass. Two masses, m1 and m2 (m1 2) are connected to the rope over the pulley. The masses are free to drop. The magnitude of the tension Ttop is ____ the sum of the tensions T1 and T2.

Accepted Answer

A)  less than 
B)  equal to 
C)  greater than 
D)  unable to tell 
E)  depends on Ttop

Question 20

A mass 2m is attached by a string to another mass m as illustrated. A force of  newtons acts on mass m to accelerate the system. The force  in the string, which acts on mass 2m, is

Accepted Answer

A)  (2/3)N 
B)  N 
C)  2N 
D)  3N 
E)  (3/2)N

Exam 4: Newtons Laws

A cricket batsman hits a ball with a bat. If the force with which the bat hits the ball is considered the action force, what is the reaction force?

Which of the following statements includes all the essential elements of Newton's first law?

Three forces, , , and , act on a mass of 4.2 kg. The forces are = 2.0 N acting to the east, = 5.0 N acting 45º to the north of east, and = 4.0 N acting 30º to the north of west. The magnitude of the net acceleration of the mass is

Which of the following is a unit of force?

A body of weight w is in free fall near the surface of Earth. What force does the body exert on the Earth?

The weight of an object is

A mass m is traveling at an initial speed v₀= 25.0 m/s. It is brought to rest in a distance of 62.5 m by a force of 15.0 N. The mass is

An astronaut lands on an Earthlike planet and drops a small lead ball with a mass of 76.5 g from the top of her spaceship. The point of release is 18 m above the surface of the planet and the ball takes 2.5 s to reach the ground. The astronaut's mass on Earth is 68.5 kg. Her weight on the planet is

Three blocks are connected by massless cords and hung by a third massless cord to a beam. Mass m₁ = 2 m₂ = 3 m₃. Mass m₁ is the lowest block and m₃ is the highest. The tension in the cord between the two highest blocks is

A particle has a mass of 6.0 $\times$ 10^-6 kg and a velocity of 800 m/s along the x axis when a force of 14.4 $\times$ 10^-5 N along the y axis acts on the particle at right angles to its velocity. The acceleration of the particle is

A ball of mass 2.0 kg is acted on by two forces, and . At t = 0 s, the particle is at rest at the origin. The velocity vector at t = 2 s is

A bell hangs from a blue rope. A red rope attached to the side of the bell is pulled in the horizontal direction. This causes the blue rope to make an angle less than 90º with the vertical. Which of the following statements is true?

A lamp of mass m hangs from a spring scale which is attached to the ceiling of an elevator. When the elevator is stopped at the fortieth floor, the scale reads mg. What does it read as the elevator slows down to stop at the ground floor?

The figure below shows two forces, F₁ and F₂, acting on an object. Use the vector diagrams to answer the next questions. -Which force vector best represents the resultant force on the object?

A net force is exerted on an object toward the north. The object

If a force F is required to extend a spring a distance 5y, how far will it be extended by force 3F?

A boy holds a bird in his hand. The reaction force to the normal force exerted on the bird by the boy's hand is the force of:

A frictionless pulley of negligible mass is hung from the ceiling using a rope, also of negligible mass. Two masses, m₁ and m₂ (m₁ < m₂) are connected to the rope over the pulley. The masses are free to drop. The magnitude of the tension T_top is ____ the sum of the tensions T₁ and T₂.

A mass 2m is attached by a string to another mass m as illustrated. A force of newtons acts on mass m to accelerate the system. The force in the string, which acts on mass 2m, is

Exam 4: Newtons Laws

A cricket batsman hits a ball with a bat. If the force with which the bat hits the ball is considered the action force, what is the reaction force?

Which of the following statements includes all the essential elements of Newton's first law?

Three forces, , , and , act on a mass of 4.2 kg. The forces are = 2.0 N acting to the east, = 5.0 N acting 45º to the north of east, and = 4.0 N acting 30º to the north of west. The magnitude of the net acceleration of the mass is

Which of the following is a unit of force?

A body of weight w is in free fall near the surface of Earth. What force does the body exert on the Earth?

The weight of an object is

A mass m is traveling at an initial speed v0 = 25.0 m/s. It is brought to rest in a distance of 62.5 m by a force of 15.0 N. The mass is

An astronaut lands on an Earthlike planet and drops a small lead ball with a mass of 76.5 g from the top of her spaceship. The point of release is 18 m above the surface of the planet and the ball takes 2.5 s to reach the ground. The astronaut's mass on Earth is 68.5 kg. Her weight on the planet is

Three blocks are connected by massless cords and hung by a third massless cord to a beam. Mass m1 = 2 m2 = 3 m3. Mass m1 is the lowest block and m3 is the highest. The tension in the cord between the two highest blocks is

A particle has a mass of 6.0 ×\times× 10-6 kg and a velocity of 800 m/s along the x axis when a force of 14.4 ×\times× 10-5 N along the y axis acts on the particle at right angles to its velocity. The acceleration of the particle is

A ball of mass 2.0 kg is acted on by two forces, and . At t = 0 s, the particle is at rest at the origin. The velocity vector at t = 2 s is

A bell hangs from a blue rope. A red rope attached to the side of the bell is pulled in the horizontal direction. This causes the blue rope to make an angle less than 90º with the vertical. Which of the following statements is true?

A lamp of mass m hangs from a spring scale which is attached to the ceiling of an elevator. When the elevator is stopped at the fortieth floor, the scale reads mg. What does it read as the elevator slows down to stop at the ground floor?

The figure below shows two forces, F1 and F2, acting on an object. Use the vector diagrams to answer the next questions. -Which force vector best represents the resultant force on the object?

A net force is exerted on an object toward the north. The object

If a force F is required to extend a spring a distance 5y, how far will it be extended by force 3F?

Two masses m1 and m2 (with m2 > m1) are connected by a massless rope hung over a frictionless light pulley. If the masses are released then the acceleration of m2 in the downward direction is given by

A boy holds a bird in his hand. The reaction force to the normal force exerted on the bird by the boy's hand is the force of:

A frictionless pulley of negligible mass is hung from the ceiling using a rope, also of negligible mass. Two masses, m1 and m2 (m1 < m2) are connected to the rope over the pulley. The masses are free to drop. The magnitude of the tension Ttop is ____ the sum of the tensions T1 and T2.

A mass 2m is attached by a string to another mass m as illustrated. A force of newtons acts on mass m to accelerate the system. The force in the string, which acts on mass 2m, is

A mass m is traveling at an initial speed v₀= 25.0 m/s. It is brought to rest in a distance of 62.5 m by a force of 15.0 N. The mass is

Three blocks are connected by massless cords and hung by a third massless cord to a beam. Mass m₁ = 2 m₂ = 3 m₃. Mass m₁ is the lowest block and m₃ is the highest. The tension in the cord between the two highest blocks is

A particle has a mass of 6.0 $\times$ 10^-6 kg and a velocity of 800 m/s along the x axis when a force of 14.4 $\times$ 10^-5 N along the y axis acts on the particle at right angles to its velocity. The acceleration of the particle is

The figure below shows two forces, F₁ and F₂, acting on an object. Use the vector diagrams to answer the next questions. -Which force vector best represents the resultant force on the object?

A frictionless pulley of negligible mass is hung from the ceiling using a rope, also of negligible mass. Two masses, m₁ and m₂ (m₁ < m₂) are connected to the rope over the pulley. The masses are free to drop. The magnitude of the tension T_top is ____ the sum of the tensions T₁ and T₂.