Question 1

Which of the following situations would be true according to Newton's law of inertia?

Accepted Answer

A)  A basketball is in flight (under the affect of gravity) and will continue to travel forward with constant horizontal velocity until stopped by another external force (such as hitting the ground, the hoop or being caught by another player) 
B)  A soccer player kicks a ball across the field. As the player applies a force to the ball with their foot, the ball applies an equal and opposite force onto the player's foot. 
C)  A javelin is in flight. Acceleration due to gravity affects the horizontal component of the javelin's flight. 
D)  A volleyball player spikes the ball. The change of motion (momentum) of the ball is proportional to the amount of force applied by the player and inversely proportional to the mass of the ball. 
E)  A shot-putter uses specific technique to maximise the distance the shot put is thrown. One aspect of this technique involves increasing the amount of time that they apply the force on the shot put so as to increase the impulse.

Question 2

Two parallel forces are acting on an object vertically upwards and one opposing force is acting on the same object vertically downwards. The forces are as follows. 
35N upwards 
63N upwards
78N downwards
Calculate the resultant force (magnitude and direction).

Accepted Answer

The answer of Two parallel forces are acting on an...

Question 3

Which of the following situations would be true according to Newton's law of reaction?

Accepted Answer

A)  A basketball is in flight (under the affect of gravity) and will continue to travel forward with constant horizontal velocity until stopped by another external force (such as hitting the ground, the hoop or being caught by another player) 
B)  A soccer player kicks a ball across the field. As the player applies a force to the ball with their foot, the ball applies an equal and opposite force onto the player's foot. 
C)  A javelin is in flight. Acceleration due to gravity can affect the vertical component of the javelin's flight but not the horizontal component. 
D)  A volleyball player spikes the ball. The change of motion (momentum) of the ball is proportional to the amount of force applied by the player and inversely proportional to the mass of the ball. 
E)  A shot-putter uses specific technique to maximise the distance the shot put is thrown. One aspect of this technique involves increasing the amount of time that they apply the force on the shot put so as to increase the impulse.

Question 4

A tennis player hits a tennis ball with a racket and the ball and racket are in contact with each other for 0.25 seconds. Use the formula ∑F = ma to calculate the force applied to the ball by the racket using the information below. 
Mass of the tennis ball: 58 gm (0.058 kg) 
Acceleration of tennis ball: 140m/s²

Accepted Answer

The answer of A tennis player hits a tennis ball...

Question 5

A force of 20N applied over a period of 4 seconds would have the same impulse as:

Accepted Answer

A)  A force of 30N applied over 2 seconds 
B)  A force of 10N applied over 10 seconds 
C)  A force of 40N applied over 2 seconds 
D)  A force of 60N applied over 1 second 
E)  A force of 90N applied over 1 second

Question 6

Calculate the weight of the person with a mass of 68kg standing on Earth's surface (acceleration due to gravity = 9.81m/s²), and on the moon (acceleration due to gravity 1.62m/s²)

Accepted Answer

The answer of Calculate the weight of the person with...

Question 7

All forces will produce or alter motion.

Accepted Answer

A) True 
 B)False

Question 8

A Rugby player (Player A) is running with the ball in his or her hands. Player B runs at Player A for a front-on tackle and tackles Player A to the ground. Considering the ball was not touched by Player B, if Player A lost his grip of the ball at the point of impact between the two players, which direction is the ball likely to travel in? Discuss this in respect to one or more of Newton's laws.

Accepted Answer

The answer of A Rugby player (Player A) is running...

Question 9

When two objects of obviously different masses (i.e. a marble and a brick) are dropped from the same height at the same time, which would hit the ground first?

Accepted Answer

A)  The heaviest object would hit the ground first because it weighs more. 
B)  Both objects will hit the ground at the same time, regardless of their mass. 
C)  The lightest object will hit the ground first because the larger mass cannot move through the air a quickly. 
D)  Whichever object hits the ground first is random and cannot be predicted. 
E)  None of the above are correct.

Exam 2: Kinetics of Linear Motion