Topic A1, A2, A3 Revision Quiz [20 marks]

A sky diver is falling at terminal speed when she opens her parachute. What are the direction of her velocity vector and the direction of her acceleration vector before she reaches the new terminal speed?

• velocity - upwards, acceleration - upwards

• velocity - upwards, acceleration -downwards

• velocity - downwards, acceleration - upwards

• velocity - downwards, acceleration -downwards

A stone is thrown downwards from the edge of a cliff with a speed of 5.0 m s⁻¹. It hits the ground 2.0 s later. What is the height of the cliff?

• 20 m

• 30 m

• 40 m

• 50 m

A ball is thrown upwards at an angle to the horizontal. Air resistance is negligible. Which statement about the motion of the ball is correct?

• The acceleration of the ball changes during its flight.

• The velocity of the ball changes during its flight.

• The acceleration of the ball is zero at the highest point.

• The velocity of the ball is zero at the highest point.

An object of mass m is sliding down a ramp at constant speed. During the motion it travels a distance x along the ramp and falls through a vertical distance h. The coefficient of dynamic friction between the ramp and the object is μ. What is the total energy transferred into thermal energy when the object travels distance x?

• mgh

• μmgh

• μmgx

• mgx

Two blocks of masses m and 2m are travelling directly towards each other. Both are moving at the same constant speed v. The blocks collide and stick together. What is the total momentum of the system before and after the collision?

• momentum before = mv,

  momentum after = mv

• momentum before = mv,

  momentum after = -mv

• momentum before = 3mv,

  momentum after = -3mv

• momentum before = 3mv,

  momentum after = 3mv

The graph shows the variation with time of the resultant net force acting on an object. The object has a mass of 1kg and is initially at rest.

What is the velocity of the object at a time of 200 ms?

• 8 m s^–1

• 16 m s^–1

• 8 km s^–1

• 16 km s^–1

A block is on the surface of a horizontal rotating disk. The block is at rest relative to the disk. The disk is rotating at constant angular velocity. What is the correct arrow to represent the direction of the frictional force acting on the block at the instant shown?

• A.

• B.

• C.

• D.

A book is at rest on a table. What is a pair of action-reaction forces for this situation according to Newton’s third law of motion?

• the force of the book on the table - the force of the book on the Earth

• the force of the table on the Earth - the force of the book on the table

• the force of the Earth on the book - the force of the book on the Earth

• the force of the Earth on the book - the force of the table on the book

The graph shows the variation of momentum with time for an object.

What net force acts on the object for the first 2.0 s and for the second 2.0 s of the motion?

• Force for first 2.0 s = 10N, Force for second 2.0 s = 0N

• Force for first 2.0 s = 20N, Force for second 2.0 s = 40N

• Force for first 2.0 s = 10N, Force for second 2.0 s = 40N

• Force for first 2.0 s = 20N, Force for second 2.0 s = 0N

The graph shows the variation of velocity of a body with time along a straight line. What is correct for this graph?

• The maximum acceleration is at P.

• The average acceleration of the body is given by the area enclosed by the graph and time axis.

• The maximum displacement is at Q.

• The total displacement of the body is given by the area enclosed by the graph and time axis.