Chapter 7 : Oscillations and Waves

Which one of the following statements is TRUE when an object performs simple harmonic motion about a central point O ?

• The acceleration is always away from O

• The acceleration and velocity are always in opposite directions

• The acceleration and the displacement from O are always in the same direction

• The graph of acceleration against displacement is a straight line

A mass-spring system can oscillate with simple harmonic motion because a compressed or stretched spring has which kind of energy?

• Kinetic

• Gravitational potential

• Mechanical

• Elastic potential

When does the pendulum reaches its maximum velocity ?

• At its lowest point

• It moves at a constant velocity

• At its highest point

• It is at rest

The period of a pendulum may be decreased by....

• Increasing the mass of the bob

• Decreasing the mass of the bob

• Moving the equilibrium point

• Shortening the length of pendulum

The bob vibrates up and down on a vertical spring. If the period of the motion is 2 seconds, the frequency....

• also 2 seconds

• two cycles per second

• one cycle per second

• one half cycle per second

Which of the following types of the waves is not a mechanical wave?

• Water waves

• Light waves

• Sound waves

• Slinky waves

The distance between the two successive crests on a wave is called...

• amplitude

• frequency

• wavelength

• speed

The second harmonic on a string fixed at both ends shows....

• a wavelength

• half a wavelength

• two wavelengths

• a wavelength and a half

In a resonating pipe which is open at both ends, there...

• are displacement nodes at each end

• are displacement antinodes at each end

• is a displacement node at one end and a displacement antinode at the other end

• none of the above

A sound source approaches a stationary observer. The frequency heard by the observer is....

• higher than the source

• lower than the source

• the same as that of the source

• equal to zero