Chapter 10, Problem 1CQ

To determine

Basic quantities on which kinetic energy and potential energy depend.

Answer to Problem 1CQ

Solution:

Kinetic energy is dependentupon “mass” and “speed”.

Potential energy depends upon

(a) Mass (m)

(b) Acceleration due to gravity (for gravitational potential energy).

(c) Separation between interacting particles.

(d) Reference position (position where we assume “zero” potential energy).

Explanation of Solution

Kinetic energy (K.E) $=\frac{1}{2}{\text{mv}}^2$

Where, m = mass of body

V = speed of body

Hence it is dependentupon “mass” and “velocity”.

Gravitational P.E $=\text{mgh}$

Here, m = mass of body, g = acceleration due to gravity, h = height of object from reference position.

$\text{U}=-G\frac{m_1\times m_2}{r^2}$

Here, $m_1$: mass of one object, ${\text{m}}_2$: mass of second object, r : separation between object

This formula is applicable when potential energy at infinite separation is equal to zero.

Hence, P.E is dependent upon position (separation between interacting), mass, nature of force field and reference position.

Conclusion:

Kinetic energy dependsupon mass and velocity, it does not depend upon position or reference position. But potential energy is property of system. It depends upon type of interaction, separation, mass and reference position.