Advertisements
Advertisements
Question
An object of mass, m is moving with a constant velocity, v. How much work should be done on the object in order to bring the object to rest?
Solution
Mass of the object = m
The initial velocity of the object = v,
The final velocity of the object = 0
Work done on the object = Change in kinetic energy of the object = Final kinetic energy − Initial kinetic energy
= `1/2 M xx (0) - 1/2 m . v^2`
= `(0) - 1/2 m . v^2`
= `-1/2 m . v^2`
The negative sign shows that the work done is opposite to the object's direction of motion.
APPEARS IN
RELATED QUESTIONS
Write an expression for the kinetic energy of an object.
Calculate the work required to be done to stop a car of 1500 kg moving at a velocity of 60 km/h?
Certain force acting on a 20 kg mass changes its velocity from 5 m s-1 to 2 m s-1. Calculate the work done by the force.
Define the term kinetic energy. Give one example of a body which possesses kinetic energy.
Write the expression for the kinetic energy of a body explaining the meaning of the symbols used.
A ball of mass M is moving with a speed v. What is its kinetic energy?
A body of 2 kg falls from rest. What will be its kinetic energy during the fall at the end of 2 s? (Assume g = 10 m/s2)
What do you understand by the kinetic energy of a body?
An apple falling from a tree is an example for kinetic energy.
Find the kinetic energy of a body of mass 5 kg moving with a uniform velocity of 10 m s-1.
