Which of the following is a type of wave that is both mechanical and longitudinal?

• A. Water waves
• B. Seismic waves
• C. Sound waves
• D. Light waves

A 60kg man stands on a weighing balance in an elevator. If the elevator accelerates upwards at 5ms\(^{-2}\), determine the reading of the scale. [g = 10ms\(^{-2}\)]

• A. 300N
• B. 600N
• C. 800N
• D. 900N

A vibrator causes water ripples to travel across the surface of a tank. The wave travels 50cm in 2s and the distance between successive crests is 5cm. Calculate the frequency of the vibrator

• A. 5Hz
• B. 6Hz
• C. 5.2Hz
• D. 25Hz

The reason for having a large number of turns in the coil of a moving coil galvanometer is to--------

• A. make the deflection of the needle proportional to the current
• B. increase the sensitivity of the galvanometer
• C. decrease the magnetic flux produced by the mag
• D. make the permanent magnet stronger

Which of the following statements is true of the diagram shown below?

• A. the two point, A and B are in phase
• B. distance AB is halgf the wavelength of the wave
• C. AC and BD are the amplitude of the wave
• D. the two points A and B represents the wave crests

How long will it take to heat 3kg of water from 28^oC to 88^oC in an electric kettle taking 6a from a 220V supply? [specific heat capacity of water = 4180 J kg^-1K^-1]

• A. 120s
• B. 570s
• C. 600s
• D. 836s

The half life of a radioactive substance is 14 days. If 48g of this substance is stored, after how many days will 1.5g of the original substance remain?

• A. 84 days
• B. 70 days
• C. 56 days
• D. 40 days

When an object is placed at the centre of curvature of a concave mirror, its image is formed at

• A. the focus
• B. infinity
• C. the centre of curvature
• D. a distance twice the radius of curvature

Which of the following will be applied when a metal Y is used to electroplate another metal X in electrolysis?

• A) X is the anode and very high current is used
• B) X is the anode and Y is the cathode
• C) Y is the cathode and X is the anode
• D) Y is the anode and very high current is used

An object of mass 0.25kg moves at a height h above the ground with a speed of 4ms^-1, if its mechanical energy at this height is 12 J, determine the value of h. [g = 10ms^-1]

• A. 0.8m
• B. 4.0m
• C. 4.8m
• D. 5.6m