Question

Determine the mechanical energy of this object. A 2 kg pendelum has a speed of 1 m/s at a height of 1/2 meter

Answer 1

Mechanical Energy: 10.81 J given that $g = 9.81 \; \text{m}\cdot\text{s}^{-2}$.

Explanation

The mechanical energy of an object is the sum of its kinetic and potential energy.

Kinetic Energy of this object:

$\text{KE} = \dfrac{1}{2} \; m \cdot v^{2} = \dfrac{1}{2} \times 2 \times 1 = 1 \; \text{J}$

Gravitational Potential Energy of this object:

$g = 9.81 \; \text{m}\cdot\text{s}^{-2}$.

$\text{PE} = m \cdot g \cdot h = 2 \times 9.81 \times \dfrac{1}{2} = 9.81 \; \text{J}$.