A 20 ton truck is pulling a 5 ton trailer.their common uniform velocity is 54 kmph.if the frictional force is 20N per both the truck and the trailer then power developed is?

Answer 1

power=work/time=20N*velocity

change 54km/hr to m/s

I am not certain what you mean 20 N per both...

Perhaps friction is 40N, I don't know what you mean by "per"

Answer 2

F= (20+5) 20=500N
velocity= 54km/h =15m/s
Power = F. V=500 x 15=7500 W
=7.5kW

Answer 3

P=F.v
v=54km/hr=15m/s
F=20N/ton
F=25×20=500N
P=500×15=7500W
=7.5kW

Answer 4

Yes, your solution is correct.