0

Guest

Courses New

A crate is pushed horizontally with 100N across a 5m floor. If the frictional force between the crate and the floor is 40N, then the kinetic energy gained by the crate is . 200j 240j 250j 300j 500j

A crate is pushed horizontally with 100N across a 5m floor. If the frictional force between the crate and the floor is 40N, then the kinetic energy gained by the crate is .
  1. 200j
  2. 240j
  3. 250j
  4. 300j
  5. 500j

Grade:12th pass

1 Answers

Samyak Jain
333 Points
4 years ago
Contant horizontal force of magnitude F = 100 N is acting on the crate. It displaces the crate by s = 5 m.
Thus, work done by this force is F.s = F.s = 100 . 5 = 500 J.
\because the direction of force is same as that of displacement.
Frictional force between crate and floor is f = 40 N. It is too acting for the displaceement s = 5 m.
Its work done is f.s = – f.s = – 40 . 5 = – 200 J.
\because the direction of force is opposite to that of displacement.
Total work done by the forces acting on the crate is 500 J + (– 200 J) = 300 J.
As we know that net work done by all the forces acting on a body is equal to change in its kinetic energy,
300 J = \DeltaKE = KEf – KEi . Assuming the crate to be at rest initially, KEi = 0.
\therefore KEf = 300 J .

Think You Can Provide A Better Answer ?

Other Related Questions on Engineering Entrance Exams

View all Questions »

ASK QUESTION

Get your questions answered by the expert for free

Answer and earn gift vouchers

Win Gift vouchers upto Rs 500/-

View courses by askIITians

Design classes One-on-One in your own way with Top IITians/Medical Professionals

Click Here Know More

Complete Self Study Package designed by Industry Leading Experts

Click Here Know More

Live 1-1 coding classes to unleash the Creator in your Child

Click Here Know More

a Complete All-in-One Study package Fully Loaded inside a Tablet!

Click Here Know More