Question

An engine develops 10kw of power . how much time to lift a mass 200 kg to height 40m

Answer 1

power=10*10^3 W

mass=200 kg

height=40 m

solution:

power= work/time

so,

time=work/power

T=f.d/p           ,work=force*distance

T=m*a*h/p      ,f=m*a

T=200*9.8*40/10*10^3      ,a=g=9.8 m/s^-2

T=7.84 sec