Kinematics, Accelerated Motion, and Dynamics

A stone sinks in water. What is a possible value for the density of the stone?

• 8 × 10² kg m–3

• 2 × 10³ kg m–3

• 8 × 10³ N m–3

• 2 × 10⁴ N m–3

Gm, Tm, μm and pm are all units of length. Which unit is the largest and which unit is the smallest? largest unit smallest unit

• Gm μm

• Gm pm

• Tm μm

• Tm pm

An aircraft travels along a horizontal path. Two of the forces that act horizontally on the aircraft are the thrust force of the engines and the force due to the wind. The vector diagram for these forces is shown. Which vector represents the resultant horizontal force acting on the aircraft due to these two forces?

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A ball travels from point X to point Y around a semicircular track of radius 1.0 m, as shown. What is the displacement of the ball from X to Y?

• 2.0 m

• 2.0 m due south

• 3.1 m

• 3.1 m due south

A rock is launched vertically upwards from the surface of the Earth and an identical rock is launched vertically upwards from the surface of Mars. Each rock is launched with an initial velocity of 12 m s–1. Each rock then reaches its maximum height above the surface before returning back down to the surface. The velocity–time graph for each rock is shown. What is the difference in the maximum heights of the two rocks?

• 12 m

• 15 m

• 19 m

• 24 m

Which statement describes the mass of an object?

• the force the object experiences due to gravity

• the momentum of the object before a collision

• the resistance of the object to changes in motion

• the weight of the object as measured by a balance

A submarine of total mass 3200 kg is at rest underwater. The total mass of the submarine is suddenly decreased by 200 kg by pumping water out of the submarine horizontally in a negligible time. The upthrust acting on the submarine is unchanged. The change in the total weight of the submarine causes it to accelerate vertically upwards. What is the initial upwards acceleration of the submarine?

• 0.613 m s–2

• 0.654 m s–2

• 9.81 m s–2

• 10.5 m s–2

A box in air slides with increasing speed down a rough slope from point P to point Q. The slope surface exerts a constant frictional force on the box. As the box moves from P to Q, there are changes to the magnitudes of its acceleration and the total resistive force acting on it. Which row describes the changes?

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Write down on your textbook:

1. The base unit of pressure is