Question

a car coasts 62.2 meters along a hil that makes a 28.3° angle with the ground. if the car's mass is 1234 kilograms, then what is the change in potential energy?

Answer 1

Given,

The distance moved by car along the hill, d=62.2 m

The angle of inclination of the hill, θ=28.3°

The mass of the car, m=1234 kg

In the above diagram h is the height at which car is after moving along 62.2 m up the hill.

The height h is given by,

`h=d\sin \theta`

On substituting the known values,

`\begin{gathered} h=62.2*\sin 28.3^(\circ) \\ =29.49\text{ m} \end{gathered}`

Potential energy is the energy possessed by an object due to its position.

The change in the potential energy of the car is given by,

`E=\text{mgh}`

Where g is the acceleration due to gravity.

On substituting the known values,

`\begin{gathered} E=1234*9.8*29.49 \\ =356.63*10^3\text{ J} \\ =356.63\text{ kJ} \end{gathered}`

Thus the change in the potential energy of the car is 356.63 kJ