The outlet of a bicycle pump is used to inflate a football as illustrated in the diagram below. Why does the pressure of the air inside the pump increases as the pump handle is slowly pushed downward at constant temperature?

• A. momentum of the air molecules are increased
• B. volume occupied by the molecules are increased
• C. frequency of collision of the air molecules with the walls of the pump is increased
• D. more air molecules are collidin with one another in the system

A moving body of mass 25.0kg undergoes a uniform retardation of 20.0ms^-2. Calculate the magnitude of the retardating force

• A. 1.25N
• B. 8.00N
• C. 45.00N
• D. 500.00N

Which of the following is a fundamental unit?

• A. Newton
• B. Watt
• C. Joule
• D. Second

The pitch of an acoustic device can be increased by

• A. decreasing the loudness
• B. increasing the intensity
• C. increasing the frequency
• D. decreasing the intensity

The distance between two successive crests of a wave is 15cm and the velocity 300ms^-1. Calculate the frequency.

• A. 2.0x10²Hz
• B. 4.5x10³Hz
• C. 2.0x10³Hz
• D. 4.5x10²Hz

For a best result using temperature to achieve an accurate measurement, it is best to use

• A. Mercury thermometer
• B. gas thermometer
• C. clinical thermometer
• D. alcohol thermometer

A simple microscope forms an image twice the size of the object. If the focal length of the lens of the microscope is 20m, how far is the object from the lens?

• A. 10m
• B. 20m
• C. 30m
• D. 40m

A uniform bar AB is balanced on a knife-edge which is 60cm from B by a mass of 22g which hangs at C 10cm from A. Calculate the mass of the bar.

• A. 133.2g
• B. 66.0g
• C. 60.0g
• D. 22.0g

After reflection from the concave mirror, rays of light from the sun converges

• A. at the radius of curvature
• B. at the focus
• C. beyond the radius of curvature
• D. between the focus and radius of curvature

The bob of a single pendulum has a mass of 0.02kg. Determine the weight of the bob [g = 10ms^-2]

• A. 0.02N
• B. 0.20N
• C. 20.00N
• D. 200.00N