Calculate the power of a crane in watts, which lifts a mass of `100 kg` to a height of `10 m` in `20 s`.
Correct Answer – C
`{:(“Given”,,”mass = m = 100″,,),(“kg”,,,,),(,,”height = h = 10 m”,,),(“time duration t = 20 s”,,,,),(,,”power =Rate of”,,),(“work done”,,,,):}`
=`(“change of PE”)/(“time”) = (“mgh”)/(t)`
`=(100 xx 9.8 xx 10)/(20)`
`=5 xx 98 = 490 W`.
Given, mass=m=100kg ltbRgt height=h=10m time duration t=20s
Power=Rate of work done
`(“Change in PE”)/(“time”)=(mgh)/(t)`
`(100xx9.8xx10)/(20)`=`5xx98=490W`