Question

1. What is the kinetic energy of an
object?
2. Write an expression for the kinetic
energy of an object.
3. The kinetic energy of an object of
mass, m moving with a velocity
of 5 ms' is 25 J. What will be its
kinetic energy when its velocity
is doubled? What will be its
kinetic energy when its velocity
is increased three times?
​

Answer 1

Answer:

In physics, the kinetic energy (KE) of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains thiskinetic energy unless its speed changes.

k=1/2mv²

Answer 2

1. Kinetic energy:

The Kinetic energy (KE) of an object is the energy possessed by the object because of its motion.

2. Expression for Kinetic Energy Of an object is given by:

                $K.E. = \frac{1}{2}mv^{2}$

3. Given,

Velocity of object (v) = 5 m/s

Kinetic Energy (K.E.) = 25 J

To Find,

Kinetic Energy of an object when its velocity is increased three times.

Solution,

We know the kinetic energy is given by

K.E.  =  $\frac{1}{2}mv^{2}$

25    =  $\frac{1}{2}$ * m * $5^{2}$

Hence,

m = $\frac{50}{25}$

m = 2

When the velocity triples,

Kinetic Energy is,

= $\frac{1}{2}mv^{2}$

= $\frac{1}{2}$ * 2 * $15^{2}$

= 225J

Therefore, its kinetic energy when its velocity is increased three times will be 225 J.