"the speed of sound at one atmosphere of pressure is 0.214 miles per second. what is the speed of sound in units of meters per second? (1 km = 0.621 mile)"

344.6 m/s

Explanation:

Speed of sound, v = 0.214 miles per second

The relation between the unit of distance mile and the unit of distance km is given in the question.

0.621 mile = 1 km

As we know that 1 km  = 1000 m

So, 0.621 mile = 1000 m

1 mile = 1000 / 0.621 m = 1610.3 m

0.214 miles = 1610.3 x 0.214 = 344.6 m

So, the speed of sound in metre per second is 344.6 m/s.

work: w = fd (given)

work done by chet   =50*1 = 50 j

work done by mika =40*2 = 80 j

work done by sara =30*1.5 = 45 j

work done by bill =60*0.5 = 30 j

students in order from the greatest amount of work done to the least is mika> chet> sara> bill

hence option (b) is correct.