Vibration, wave and light

What is vibration?

• • A motion in a straight line

• • A repeated back-and-forth motion around a fixed point

• • An up and down motion in space

• • A circular motion

What happens when the amplitude of a vibration increases?

• • The vibration becomes weaker

• • The vibration becomes slower

• • The vibration becomes stronger

• • The vibration becomes silent

If a pendulum completes 20 vibrations in 10 seconds, what is its frequency?

• • 0.5 Hz

• • 2 Hz

• • 10 Hz

• • 20 Hz

What is the relationship between period (T) and frequency (f)? (choose the correct formula!)

• T = 1/f

• Period (T) and frequency (f) are unrelated quantities.
• T= f

• T = f x n

What unit is used to measure the frequency of a vibration?

• • Seconds

• • Meters

• • Hertz

• • Joules

What is the key difference between mechanical and electromagnetic waves?

• • Mechanical waves travel faster

• • Electromagnetic waves require a medium

• • Mechanical waves require a medium

• • Electromagnetic waves have longer wavelengths

What type of wave has particles moving perpendicular to the wave direction?

• • Longitudinal wave

• • Transverse wave

• • Electromagnetic wave

• • Mechanical wave

In a longitudinal wave, compressions are:

• • Areas where particles are spread out

• • Areas where particles are closer together

• • The highest points of the wave

• • The lowest points of the wave

The distance a wave travels during one complete cycle is called its:

• • Frequency

• • Amplitude

• • Period

• • Wavelength

A wave with a speed of 340 m/s and frequency of 50 Hz has a wavelength of:

• • 6.8 m

• • 6.5 m

• • 5.8 m

• • 7.5 m