Bennett Mechanical Test Acoustics and Optics 3

Question 1

Why can't sound travel through outer space?

Accepted Answer

There is no medium to carry it

Answer

Sound needs a material medium to vibrate through, and space is a near vacuum.

Question 2

A concave (diverging) lens causes parallel light rays to:

Accepted Answer

Spread apart

Answer

A concave lens diverges parallel rays, making objects appear smaller.

Question 3

The pitch of a guitar string rises when the string is made:

Accepted Answer

Shorter and tighter

Answer

Shorter, tighter strings vibrate at higher frequencies, producing a higher pitch.

Question 4

White light passing through a prism separates into colors because each color:

Accepted Answer

Bends by a different amount

Answer

Different wavelengths refract by different amounts, spreading white light into a spectrum.

Question 5

A material that absorbs sound well, like foam, is used to:

Accepted Answer

Reduce echoes

Answer

Soft, porous materials absorb sound energy and cut down reflections and echoes.

Bennett Mechanical Test Practice Test