Question

Given mass = 100kg, rate of falling is 8 m in 4 seconds. Load = 500 kgf. If efficiency is 75% then to what height the load will rise in 4 seconds (take g = 10m/sec^2)

Answer 1

Given, mass=100kg

height,S=8m. g=10m/s^2

In 1st case,

time= 4s

Work done =F❌S

=100❌10❌8 joule

=8000j

power=W/t

=8000/4

=2000 watt

In 2nd case,

force=500kgf=500❌10=5000N

efficiency=0.75

t=4s i.e same

Power=F❌S(distance)/ t

S=P❌t/F

=2000❌4/5000metre

=1.6metre