**1. Two objects undergo an inelastic collision. Which of the following is correct in respect of both the conservation of momentum and the conservation of total energy of the system?**

**2. A gas atom strikes a wall with speed v at an angle θ to the normal to the wall. The atom rebounds at the same speed v and angle θ .**

Which of the following gives the magnitude of the momentum change of the gas atom?

**3. The initial kinetic energy of a block moving on a horizontal floor is 48 J. A constant frictional force acts on the block bringing it to rest over a distance of 2 m. What is the frictional force on the block?**

**4. Objects A and B collide together. They end up joined together and stationary. During the collision, a force + F is exerted on object A by object B . According to Newton’s third law, there will also be a force of**

**5. An object falls from rest from a height h close to the surface of the Moon. The Moon has no atmosphere.**

When the object has fallen to height `h/4` above the surface, what is

**6. A car travelling at a constant velocity covers a distance of 100 m in 5.0 s. The thrust of the engine is 1.5 kN. What is the power of the car?**

**7. An object is at rest at time t = 0 . The variation with t of the acceleration a of the object is shown from t = 0 to t = 20 s .**

What is the speed of the object when t=15 s?

**8. A boy runs along a straight horizontal track. The graph shows how his speed v varies with time t.**

After 15 s the boy has run 50 m. What is his instantaneous speed and his average speed when *t *= 15 s?

**9. A graph shows the variation of force acting on an object moving in a straight line with distance moved by the object. Which area represents the work done on the object during its motion from P to Q?**

**10. Two objects**

*m*_{1} and *m*_{2} approach each other along a straight line with speeds *v*_{1} and *v*_{2} as shown. The objects collide and stick together.

What is the total change of linear momentum of the objects as a result of the collision?

**11. Two balls of different mass are dropped from the top of a tall building one after the other. The distance between the balls**

**12. Which of the following is a condition for an object to be in translational equilibrium?**

**13. A projectile is fired horizontally from the top of a cliff. The projectile hits the ground 4 s later at a distance of 2 km from the base of the cliff. What is the height of the cliff?**

**14. The momentum of a particle stays constant provided that**

**15. The diagram shows a girl attempting (but failing) to lift a heavy suitcase of weight W . The magnitude of the vertical upwards pull of the girl on the suitcase is P and the magnitude of the vertical reaction of the floor on the suitcase is R .**

Which equation correctly relates W, P and R?

**16. A net force acts on a body. Which characteristic of the body will definitely change?**

**17. A stone is thrown vertically upwards from the surface of Earth. Which of the following quantities will not become zero while the stone is in the air?**

**18. A railway engine of mass m moves along a horizontal track with uniform speed v . The total resistive force acting on the engine is F .**

Which of the following is the power of the engine?

**19. A ball of mass 0.40 kg travels horizontally and strikes a vertical wall with a speed of 5.0**

ms^{–1}. It rebounds horizontally with a speed of 3.0 ms^{–1}. The ball is in contact with the wall for a time of 0.20 s.

What is the average magnitude of the force exerted by the ball on the wall?

**20. An object is projected vertically upwards at time t = 0. Air resistance is negligible. The object passes the same point above its starting position at times 2 s and 8 s.**

If g = 10 m s^{–2}, what is the initial speed of the object?

**21. Which of the following is proportional to the net external force acting on a body?**

**22. Which statement applies to an object in translational equilibrium?**

**23. A lift (elevator) is operated by an electric motor. It moves between the**

10^{th} floor and the 2^{nd }floor at a constant speed. One main energy transformation during this journey is

**24. Child X throws a ball to child Y. The system consists of the ball, the children and the Earth. What is true for the system when the ball has been caught by Y?**

**25. The graph shows how the displacement d of an object varies with time t . The tangent to the curve at time**

t_{1} is also shown.

Which of the following gives the speed of the object at point P?

**26. An object, initially at rest, travels a distance d in a time t at a constant acceleration. What is the time taken for the object to travel 16d from rest at the same acceleration?**

**27. Which of the following is an elastic collision?**

**28. An egg dropped on the floor is likely to break. However, when it is wrapped in a cloth it is less likely to break. This is because the cloth**

**29. The distance travelled by the object during the first 4.0 seconds is**

**30. An object of mass**

_{1} has a kinetic energy *E*_{1}. Another object has a mass *m*_{2} and kinetic energy *E*_{2}. The objects have the same momentum. What is the ratio `E_1/E_2?`

**31. The graph shows the variation with time t of the force F acting on an object of mass 15 000 kg.**

The object is at rest at *t *= 0.

What is the speed of the object when *t *= 30 s?

**32. A constant force of 12 N is applied for 3.0 s to a body initially at rest. The final velocity of the body is.**

6.0m s^{–1}. What is the mass of the body?

**33. A block of mass m is moving at constant velocity v along a frictionless surface that is height h above the ground.**

Which expression gives the work necessary to maintain the constant velocity?

**34. A vehicle is driven up a hill at constant speed. Which of the following best describes the energy changes involved?**

**35. Each side of a metal cube is measured to be 2.0 cm ± 0.20 cm. What is the absolute uncertainty in the calculated volume of the cube?**

**36. A rubber ball, travelling in a horizontal direction, strikes a vertical wall. It rebounds at right angles to the wall. The graph below illustrates the variation of the ball’s momentum p with time t when the ball is in contact with the wall.**

Which of the following statements is true?

**37. Two balls X and Y with the same diameter are fired horizontally with the same initial momentum from the same height above the ground. The mass of X is greater than the mass of Y. Air resistance is negligible.**

What is correct about the horizontal distances travelled by X and Y and the times taken by X and Y to reach the ground?

**38. The time taken for a stone dropped from rest to fall vertically through 16 m is 2.0 s. Based on these measurements, what is the best estimate for the acceleration of free fall?**

**39. Two identical spheres, each of mass m and speed v, travel towards each other on a frictionless surface in a vacuum.**

The spheres undergo a head-on elastic collision.

Which statement correctly describes the spheres after the collision?

**40. A force which increases uniformly from 0 to a maximum value of F is applied to an object. The object does not move until the force exceeds 0.5F. As the force increases from 0.5F to F the object moves a distance x in the direction of the force. What is the work done by this force?**

**41. A student makes three statements about situations in which no work is done on an object.**

I. The object is moving with uniform circular motion.

II. A force is applied to the object in the direction of its velocity.

III. A force is applied to the object in a direction opposite to its motion.

Which of the above statements is/are correct?

**42. Which of the following is the condition for a body to be in translational equilibrium?**

**43. An ice-hockey puck is slid along ice in a straight line. The puck travels at a steady speed of 20**

ms^{–1} and experiences no frictional force. How far does the puck travel in 2.5 s?

**44. An object is released from rest in the gravitational field of the Earth. Air resistance is negligible. How far does the object move during the fourth second of its motion?**

**45. A ball of mass m travels horizontally with speed v before colliding with a vertical wall. The ball rebounds at speed v in a direction opposite to its initial direction. What is the magnitude of the change in momentum of the ball?**