Home
Class 11
PHYSICS
A body dropped from a height H reaches t...

A body dropped from a height H reaches the ground with a speed of 1.2 `sqrt(gH)`. Calculate the work done by air friction.

Text Solution

Verified by Experts

The forces acting on te body are the force of gravit and the air friction. By work energy theorem, the total work done on the body is
`W=1/2m(1.2sqrt(gH))^2-0=0.72mgH`
The work done by the force of gravity is mgh. Hence, the work done by the air friction is
`0.72mgH-mgH=00.28mgH.
Promotional Banner

Topper's Solved these Questions

  • WORK AND ENERGY

    HC VERMA|Exercise Short Answer|15 Videos

  • WORK AND ENERGY

    HC VERMA|Exercise Objective 1|10 Videos

  • WORK AND ENERGY

    HC VERMA|Exercise Exercises|64 Videos

  • WAVE MOTION AND WAVES ON A STRING

    HC VERMA|Exercise Exercises|57 Videos

Similar Questions

Explore conceptually related problems

A body dropped from a height 'H' reaches the ground with a speed of 1.1 sqrt(gH) . Calculate the work done by air friction :

A body of mass 'm' drpped from a height 'h' reaches the ground with a speed of 0.8 sqrt(gh) . The value of warkdone by the air-friction is ,

A body of mass 'm' drpped from a height 'h' reaches the ground with a speed of 0.8 sqrt(gh) . The value of warkdone by the air-friction is ,

A body of mass m when released from rest from a height h, hits the ground with speed sqrt(gh) . Find work done by air resistance force.

A body is thrown from a height h with speed, u it hits the ground with speed v

A particle is dropped from height h, just before striking the ground its velocity is 0.8 sqrt(gh) . Find work done by air resistance. (assume mass to m)

A body dropped from a height of 5m. Reaches the ground in 1 s. if it takes 2 s to reach the ground , find the height from which it is dropped.

A body of mass 'm is drhopped from a height 'h'. The speed with which body hits the ground is sqrt(0.9gh) Find the work done by air-resistance furing its fall.

A drop of mass 2.0 g falls from a cliff of height 1.0 km It hits the ground with a speed of 50.0 ms^(-1). The work done by the resistive force is

A stone of mass 20 g falling from height of 2 km hits the ground with a speed of 200 ms^-1 . The work done by the gravitational force is