EmSAT Physics Flashcards

What is the speed of light in a vacuum?

Answer: 3 × 10⁸ m/s

The speed of light in a vacuum is approximately 3 × 10⁸ m/s (300,000 km/s). This is a fundamental constant of nature denoted by c.

What type of wave is sound?

Answer: Longitudinal wave

Sound is a longitudinal (mechanical) wave where particles vibrate parallel to the direction of wave propagation. It requires a medium (solid, liquid, or gas) to travel.

What happens to the frequency of a wave when its wavelength decreases (speed constant)?

Answer: Frequency increases

Wave speed = frequency × wavelength (v = fλ). If speed is constant and wavelength decreases, frequency must increase to maintain the equation.

What is the Doppler effect?

Answer: Change in observed frequency due to relative motion

The Doppler effect is the change in observed frequency of a wave due to the relative motion between the source and the observer. A siren sounds higher as it approaches and lower as it moves away.

Which type of electromagnetic wave has the highest frequency?

Answer: Gamma rays

Gamma rays have the highest frequency (and shortest wavelength) in the electromagnetic spectrum. They are produced by nuclear reactions and have the most energy.

What is the law of reflection?

Answer: The angle of incidence equals the angle of reflection

The law of reflection states that the angle of incidence equals the angle of reflection, both measured from the normal to the reflecting surface.