Question

What is difference between rotational kinetic energy and linear kinetic energy. Write down their formulas and compare them.

Answer 1

Explanation

• Kinetic energy is the energy associated with the motion of a body.
• Linear kinetic energy describes the energy of an object that moves in linearly.
• Whereas rotational kinetic energy is the energy, related to an object that spins about an axis.
• The Linear kinetic energy is given by

$\qquad\qquad \begin{aligned} \small E_k&=\small \frac{1}{2}mv^2 \end{aligned}$

• That for the rotational motion is

$\qquad\qquad \begin{aligned} \small E_{k-r}&=\small \frac{1}{2}I \omega^2 \end{aligned}$

• Yet the 2 formulas are analogous and hence $\small I \implies m,\quad \omega\implies v$ .