1. A box of mass m is pulled across a horizontal surface with a force $F$ as shown in the diagram. The coefficient of dynamic friction between the box and the surface is µ. What is the energy transferred to thermal energy while a box is moved by a distance of d?

2. A spring with spring constant $k$ is extended by a distance $x$.

The uncertainty of $k$ is 2% and that of $x$ is 3%.

What is the uncertainty of the potential energy stored in the spring?

3. A ball is projected with an initial speed of 2 m s−1 , making an angle of 35o with the horizontal as shown.

Which expression gives the vertical component of the velocity vector?

4. A coin is tossed vertically upwards from a height of 1.5 m. What is the maximum height reached above the ground if the coin was projected with an initial velocity of 3.0 m s−1? (Take g=10 m s−2)

5. A box is pulled up a slope inclined at 30° to the horizontal by a force of F. The angle between the direction of $F$ and the plane of the incline is also 30°.

The box is pulled a distance of d up along the slope. What is the work done by F on the box?

6. An object of mass M on a string moves in a circle of radius r at a constant speed.

 

 

 

 

Which of the following statements is true about the motion of the object:

• I.  The resultant work done on the object is zero.
• II.  The velocity of the object is constant.
• III.  The object is accelerating

7. A ball rolls horizontally off the edge of the top of a cliff. It hits the ground at a distance 2.0$m$ from the base of the cliff with a vertical speed of 20 m s−1. What is the height of the cliff?

8. Which of the following is not a suitable SI unit of energy?

9. An object with a weight $W$ connected to one end of a rod of negligible mass rotates at constant speed in a vertical plane.

 

When the object is at the top position of the circular path, the tension on the rod is zero. What is the magnitude of tension at the bottom position of the circular path?

10. A ball of mass $m$ is falling vertically through the air. The drag force acting on the ball is given by kv2 where $k$ is a constant and $v$ is the speed of the ball. What is the maximum speed reached by the ball?

11. An electric motor is used to raise a block of mass 18.0 kg vertically to the top of a building at a constant speed of 1.5 m s−1. If the power rating of the motor is 297 W, calculate the efficiency of the motor.

12. A table tennis ball of mass m is dropped on a level surface from a height $H$. The ball rebounds to a height $h<H$ after impact. Which of the following is correct about the nature of the collision and magnitude of the change in momentum ($\Delta p$) of the ball as a result of this impact?

13. A car enters a roundabout with a speed $v$. The dotted line shows the path of the car. The road is slightly banked at an angle to the horizontal.

The coefficient of friction between the tires of the car and the road is $\mu$. When $\mu$ decreases, which of the following changes could prevent the car from slipping away on this roundabout?

14. An object moves $9m$ east, then 12m north.

What is the magnitude of the total displacement of this object?

15. An airplane in straight level flight experiences a lift force $L$ that is proportional to the speed of the plane and is perpendicular to the axis of the wings and as shown in diagram.

 

 

On a banked turn at the same speed, the wings make an angle $\theta$ with the horizontal.

Which of the following gives the centripetal force on the airplane?

16. Two trucks X and Y are pulling a car out of thick mud along a straight path. The only other horizontal force acting on the car is a drag force opposite to the direction of motion. The diagram shows the direction of the force applied by truck $X$ and the direction of motion of the car.

Which of the following vectors shows the direction of the force applied by truck $Y$?

17. A mass is attached to the mirror of a car by a string. As the car accelerates to the left, the string makes an angle with the vertical as shown in the diagram below.

Which of the following shows the correct free-body diagram that represents the forces acting on this mass when it is accelerating?

18. A spring of negligible mass and length of lo is attached to a fixed point. When the spring is extended by an external force $F$, the length of the spring increases to $l$. The graph shows how the length of the spring varies with the tension in spring. The tension in the spring is equal to $k\Delta l$, where k is a constant, and $\Delta l$ is the extension of the spring.

What are the gradient and y-intercept of the graph?

19. A pilot intends to fly a plane from point $A$ to point $B$. Due to strong winds, she points the nose of the plane in the direction shown by the vector $P$. Which of the choices below best represents the direction of the wind encountered by the plane?

20. A car of mass $m$ and a truck of mass $3m$ travelling in opposite directions collide and stick together. The speeds of the car and the truck just before the crash are $2v$ and $v$ respectively. What is their speed after the collision

21. Which of the following is a vector quantity?

 

22. The graph shows the variation with time $t$ of the velocity $v$ of a car traveling along a straight and level road.

What time does it take for the car to travel a distance of 31.5 m from $t$ = 0?

23. An object moves at constant velocity for a period of time, after which it undergoes uniform deceleration until it comes to rest. A velocity-time graph is plotted for this motion. On the graph, which of the following represents the displacement of the object?

24. Which of the following units is not a unit of power?

 

25. A projectile is fired with a launch angle $\alpha$ above the horizontal and an initial velocity of 40 m s^−1 towards a cliff that rises 300 m above the plane of projection. The cliff is 120 m from the launch point.

Assuming that air resistance has no effect on the motion, then the time of flight taken by the projectile to reach the plane of the cliff, is given by;