Question

a car is accelerated on a levelled road and attains a velocity four times its initial velocity . in this process, how does thepotential energy of the car change

Answer 1

Hello!
This is present in the study material.

Suppose a body of mass m is moving with a uniform velocity u. Let an external force be applied on it so that it gets displaced by distance s and its velocity becomes v. In this scenario, the kinetic energy of the moving body is equal to the work that was required to change its velocity from u to v.

Thus, we have the velocity−position relation as:

v2 = u2 + 2as

OR



Where, a is the acceleration of the body during the change in its velocity

Now, the work done on the body by the external force is given by:

W = F × s

F = ma …(ii)

From equations (i) and (ii), we obtain:


If the body was initially at rest (i.e., u = 0), then:


Since kinetic energy is equal to the work done on the body to change its velocity from 0 to v, we obtain:

2v^2