Apiston in a gas supply pump has an
area of 500 cm2 and it moves a distance
of 30 cm during one stroke. the pump
moves the gas against a fixed pressure
of 4000 pa. the work done by the piston
during on strikes is
a. 60 joule
b. 70 joule
c. 55 joul
d. none

A. 60 Joule

Explanation:

First find the force given the pressure and area.

F = AP

F = 500 cm² × (1 m / 100 cm)² × 4000 N/m²

F = 200 N

Now find the work:

W = Fd

W = 200 N × 30 cm × (1 m / 100 cm)

W = 60 J

v=ir = 3x15 =45 v

when jerome paddle in flowing river towards east the net speed of jerome will increase

so the net speed of jerome will be given as

now the speed of paul will be same as it is given as he is running on the ground

so

so here we can say since the speed of jerome is more so he will win the race

now as we know the distance so the time difference is given as

so jerome will reach first and the time difference will be 203.55 s or 3.4 min