IB Physics Standard Level

1. Which quantity has the same units as those for energy stored per unit volume? A. Density B. Force C. Momentum D. Pressure

2. A list of four physical quantities is • acceleration • energy • mass • temperature How many scalar quantities are in this list? A. 1 B. 2 C. 3 D. 4

3. An object of mass 2m moving at velocity 3v collides with a stationary object of mass 4m. The objects stick together after the collision. What is the final speed and the change in total kinetic energy immediately after the collision? Final speed Change in total kinetic energy A. v 3 mv 2 B. v 6 mv 2 C. 2v 3 mv 2 D. 2v 6 mv 2

4. An object of mass 1 kg is thrown downwards from a height of 20 m. The initial speed of the object is 6 m s–1. The object hits the ground at a speed of 20 m s–1. Assume g = 10 m s–2. What is the best estimate of the energy transferred from the object to the air as it falls? A. 6 J B. 18 J C. 182 J D. 200 J

Turn over 5. An object of mass 8.0 kg is falling vertically through the air. The drag force acting on the object is 60 N. What is the best estimate of the acceleration of the object? A. Zero B. 2.5 m s–2 C. 7.5 m s–2 D. 10 m s–2

6. P and Q leave the same point, travelling in the same direction. The graphs show the variation with time t of velocity v for both P and Q. Q P 0 0 1 2 3 4 5 6 7 8 20 40 v / m s–1 t / s What is the distance between P and Q when t = 8.0 s? A. 20 m B. 40 m C. 60 m D. 120 m

7. Three forces act on a block which is sliding down a slope at constant speed. W is the weight, R is the reaction force at the surface of the block and F is the friction force acting on the block. R W F In this situation A. there must be an unbalanced force down the plane. B. W = R. C. F = W. D. the resultant force on the block is zero.

8. A balloon rises at a steady vertical velocity of 10 m s–1. An object is dropped from the balloon at a height of 40 m above the ground. Air resistance is negligible. What is the time taken for the object to hit the ground? A. 10 s B. 5 s C. 4 s D. 2 s

Turn over 9. An object of mass m strikes a vertical wall horizontally at speed U. The object rebounds from the wall horizontally at speed V. What is the magnitude of the change in the momentum of the object? A. 0 B. m(V-U) C. m(U-V) D. m(U+V)

10. A horizontal force F acts on a sphere. A horizontal resistive force kv 2 acts on the sphere where v is the speed of the sphere and k is a constant. What is the terminal velocity of the sphere? A. k F B. k F C. F k D. F k

11. An ideal gas of constant mass is heated in a container of constant volume. What is the reason for the increase in pressure of the gas? A. The average number of molecules per unit volume increases. B. The average force per impact at the container wall increases. C. Molecules collide with each other more frequently. D. Molecules occupy a greater fractional volume of the container.

12. A substance in the gas state has a density about 1000 times less than when it is in the liquid state. The diameter of a molecule is d. What is the best estimate of the average distance between molecules in the gas state? A. d B. 10d C. 100d D. 1000d

13. A bicycle of mass M comes to rest from speed v using the back brake. The brake has a specific heat capacity of c and a mass m. Half of the kinetic energy is absorbed by the brake. What is the change in temperature of the brake? A. Mv mc 2 4 B. Mv mc 2 2 C. mv Mc 2 4 D. mv Mc 2 2

14. An object moves with simple harmonic motion. The acceleration of the object is A. constant. B. always directed away from the centre of the oscillation. C. a maximum at the centre of the oscillation. D. a maximum at the extremes of the oscillation.

15. A travelling wave has a frequency of 500 Hz. The closest distance between two points on the wave that have a phase difference of 60 rad 3 π       is 0.050 m. What is the speed of the wave? A. 25 m s–1 B. 75 m s–1 C. 150 m s–1 D. 300 m s–1

Turn over 16. What changes occur to the frequency and wavelength of monochromatic light when it travels from glass to air? Frequency Wavelength A. stays the same stays the same B. stays the same increases C. increases stays the same D. decreases increases

17. The air in a pipe, open at both ends, vibrates in the second harmonic mode. Q P What is the phase difference between the motion of a particle at P and the motion of a particle at Q? A. 0 B. 2 π C. π D. 2π

18. A metal wire has n free charge carriers per unit volume. The charge on the carrier is q. What additional quantity is needed to determine the current per unit area in the wire? A. Cross-sectional area of the wire B. Drift speed of charge carriers C. Potential difference across the wire D. Resistivity of the metal

19. An electric motor raises an object of weight 500 N through a vertical distance of 3.0 m in 1.5 s. The current in the electric motor is 10 A at a potential difference of 200 V. What is the efficiency of the electric motor? A. 17 % B. 38 % C. 50 % D. 75 %

20. A current in a wire lies between the poles of a magnet. What is the direction of the electromagnetic force on the wire? A. B. C. D. N S current