What is the magnitude of the resultant force acting on the ball?

• A) 3.5 N
• B) 7 N
• C) 1 N
• D) 5 N

Which statement is correct?

• A) Static friction is always smaller than dynamic friction.
• B) Static friction is always larger than or equal to dynamic friction.
• C) Static frction is smaller than dynamic friction under the right circumstances.
• D) They are equal.

If we place a ball in a liquid, and it starts accelerating back up, out of the liquid, then which statement is correct?

• A) The weight of the liquid that the ball displaces is larger than its own weight.
• B) The weight of the liquid that the ball displaces is smaller than its own weight.
• C) The drag force that acts on the ball is larger than its weight.
• D) The density of the ball is larger than the desnity of the liquid.

What is the difference between an elastic and inelastic collission?

• A) In an elastic collision momentum is conserved, whereas in inelastic collisions it is not.
• B) In an elastic collision kinetic energy is conserved while momentum is not, and in an inelastic collision kinetic energy and momentum is conserved.
• C) Both conserve momentum, but only elastic conserves kinetic energy as well.
• D) Elastic collisions conserve kinetic energy, while inelastic does not

What does the free body diagramm of the pendulum below look like when it is rotating in a circle of constant radius?

Answers:

A)

B)

C)

D)

A ball of 1 kg is shot horizontally at a perfectly still wall at 5 \(\text{ms}^{-1}\), and rebounds with a speed of 5 \(\text{ms}^{-1}\). What is its change in momentum?

• A) 5 \(\text{kgms}^{-1}\)
• B) 0 \(\text{kgms}^{-1}\)
• C) 10 \(\text{kgms}^{-1}\)
• D) 25 \(\text{kgms}^{-1}\)

A \(\text{80 kg}\) person stands in an elevator which is accelerating upwards at \(\text{2 m/s}^2\). What is the apparent weight of the person?

• A) \(\text{160 N}\)
• B) \(\text{40 N}\)
• C) \(\text{944 N}\)
• D) \(\text{624 N}\)

A body is held in translational equilibrium by 4 forces of magnitude, \(\text{1 N, 5 N, 10 N, 15 N}\). Which of the following statements are correct?

i. The forces are perpendicular to each other.

ii. The vector sum of the forces is 0.

iii. The forces can't be in the same direction.

• A) i only
• B) i and ii
• C) ii and iii
• D) Neither

When a book rests on a table, it experiences a gravitational force. According to Newton's 3rd law, which of these forces is the pair of this force?

• A) The force of the book pulling the Earth.
• B) The normal force of the book on the table.
• C) The normal force of the table on the book.
• D) The frictional force between the book and the table's surface.

A force \( F \) is applied to a block of mass \( m \). The speed of the mass changes from \( v_2 \) to \( v_1 \). What is the impulse received by the block?

• A) \( m(v_1 - v_2^2) \)
• B) \( m(v_1^2 - v_2) \)
• C) \( m(v_2 - v_1) \)
• D) \( m(v_1 - v_2) \)

Which of these is the definition of the SI unit for force?

• A) The weight of a \( 1 \, \text{kg} \) block.
• B) Change in momentum over unit time.
• C) Force required to accelerate a block of \( 1 \, \text{kg} \) at \( 1 \, \text{ms}^{-2} \) in the direction of the force.
• D) The weight of a \( 0.1 \, \text{kg} \) block.

The momentum of an object increases uniformly from 0 to \( 10 \, \text{kg} \cdot \text{m/s} \) in 5 seconds. What is the net force acting on the object during this time?

• A) \( 5 \, \text{N} \)
• B) \( 50 \, \text{N} \)
• C) \( 2 \, \text{N} \)
• D) \( 15 \, \text{N} \)

A ball of mass \( 2m \) rolls to the right with speed \( v \), while another ball rolls left with a mass of \( m \) and speed \( 2v \). They collide. What is true after the collision?

• A) Total momentum will be \( 0 \).
• B) The blocks will have a speed of \( 0 \).
• C) Total momentum will be \( 2mv \).
• D) Momentum of each block will be \( 2mv \).

A satellite orbits Jupiter in a circular orbit. What is true about the resultant force on the satellite?

i. It is the gravitational force.

ii. It is equal to its mass divided by its acceleration.

iii. It is equal to the centripetal force.

• A) i and iii
• B) ii only
• C) ii and iii
• D) i and ii

A satellite orbits Jupiter in a circular orbit. Which of the following listed quantities does not remain constant?

• A) Velocity
• B) Speed
• C) Centripetal force
• D) Kinetic energy