Question

A spring is kept compressed by a toy car with a mass of 100g On releasing the pressure the car moves out with a speed of 0.5ms^-1. Calculate the potential energy of the compressed spring?

Answer 1

Step 1: Given data,

1. The mass of the toy car = $100g=\frac{100}{1000}kg$
2. the velocity of the car = 0.5ms^-1

Step 2: Calculate the kinetic energy,

The Spring stores the Potential energy that converts into kinetic energy, from the law of conservation of energy The potential energy stored in the spring is equal to the kinetic energy of the toy car.

$$\begin{gathered} Kineticenergy=\frac{1}{2}m{v}^2 \\ =\frac{1}{2}\times \frac{100}{1000}\times {\left(0.5\right)}^2 \\ =\frac{1}{2}\times \frac{25}{100} \\ =\frac{12.5}{1000} \\ =0.0125J \end{gathered}$$

According to the law of conservation of energy, the potential energy stored in the spring is equal to the kinetic energy of the spring.

Thus, the potential energy stored in the spring is $0.0125\text{J}$.