A girl is standing 150m in front of a tall building, fires a shot with starting pistol. A boy standing 350m behind her, hears two bangs 1s apart. From this information what is speed of sound in air?

300 m/s

Explanation:

The difference in time between the two bangs is 1 s.

Thus;

t2 - t1 = 1

We know that distance/time = speed.

Thus;

d2/v - d1/v = 1

Multiply through by v to get;

d2 - d1 = v

Where v is speed of sound in air.

d1 = 350 m

d2 = (150 × 2) + 350 = 650 m

Thus;

v = d2 - d1 = 650 - 350 = 300 m/s

iron would move it is magnetic there is a mag field around the current in the wire