Question

What is the SI unit of energy? Define it.Calculate the kinetic energy of a body of mass 2 kg moving with a velocity of 0.1 metre per second.
[5 MARKS]

Answer 1

Definition: 1 Mark
Equation: 1 Mark
Problem: 3 Mark

1. Joule
2. Joule is defined as the work done by a force of one newton acting on an object to move it through a distance of one meter in the direction the force is applied
3. The formula for calculating kinetic energy is:

Kinetic energy $=\frac{1}{2}m{v}^2$

Here, Mass, m = 2 kg

And, Velocity, v = 0.1 m/s

So, putting these values in the above formula, we get:

Kinetic energy $=\frac{1}{2}\times 2\times (0.1{)}^2$

$=\frac{1}{2}\times 2\times 0.1\times 0.1$

$=0.01J$

Thus, the kinetic energy of the body is 0.01 joule.