Home
Class 11
PHYSICS
One man takes 1 minute to raise a box to...

One man takes 1 minute to raise a box to a height of 1 metre and another man takes 1/2 minute to do so. The energy of the two is

A

different

B

same

C

energy of the first is more

D

energy of the second is more

Text Solution

Verified by Experts

The correct Answer is:
B

Energy required = mgh. In both cases, h is the same. Hence, energy given by both is same. [It is worth noting here that powers of two men will be different a power is the energy expense per unit time and times are different here.]
Promotional Banner

Topper's Solved these Questions

  • WORK , ENERGY AND POWER

    NCERT FINGERTIPS|Exercise Power|13 Videos
  • WORK , ENERGY AND POWER

    NCERT FINGERTIPS|Exercise Collisions|15 Videos
  • WORK , ENERGY AND POWER

    NCERT FINGERTIPS|Exercise The Potential Energy Of A Spring|6 Videos
  • WAVES

    NCERT FINGERTIPS|Exercise Assertion And Reason|15 Videos

Similar Questions

Explore conceptually related problems

One coolie takes 1min to raise a box through a height of 2m . Another one takes 30s for the same job and does the same amount of work. Which one of the two has greater power and which one uses greater enegy?

One coolie takes 1 min to raise a box through a height 2 m . Another takes 30 s for the same job and does the same job and does the same amount of work. Which one of these two has a greater power and which one uses greaster energy ?

A man walks for 1 minute at a speed of 1m/s and then runs for 2 minute at 3m/s. What is the average speed of the man?

Ravish takes 2 1/5 minutes to walk across the school ground. Rahul takes 7/4 minutes to do the same. Who takes less time and by what fraction?

A man takes 3 hours 45 minutes to row a boat 15km downstream of a river and 2 hours 30 minutes to cover a distance of 5km upstream. Find the speed of the river current in km/hr .

A body of mass m kg lifted by a man to a height of one metre in 30 sec . Another man lifted the same mass to the same height in 60 sec . The work done by them are in the ratio.