How long would it take for a sound impulse to travel through an aluminum rod 150 meters long?
s
0.029
0.29
3.4
34

0.029 s

Explanation:

The speed of sound in aluminim is v = 5100 m/s.

The sound travels in aluminium by uniform motion (constant speed), so we can find the time it takes to cover a certain distance by using the equation:

where d is the distance covered, in this case d = 150 m. Substituting the numbers into the equation, we find

one person pulls 90n one way and the other has 100n pulling the other way.

so the net force = 90 - 100 = -10n,

or the ans can be 10n if the picture shows -90n and 100n instead.