Question

a car moving at 30 m/s crashes into a tree and stops in 0.2 s. calculate the force the seat belt exerts on a passenger in the car to bring him to a halt. the mass of the passenger is 74 kg (enter the magnitude )

Explanation:

Step1: Calculate the acceleration

We use the formula \(a=\frac{v - u}{t}\), where \(u = 30\space m/s\), \(v=0\space m/s\), and \(t = 0.2\space s\).

$$a=\frac{0 - 30}{0.2}=- 150\space m/s^{2}$$

The negative sign indicates deceleration.

Step2: Calculate the force

According to Newton's second law \(F = ma\). Given \(m = 74\space kg\) and \(a=150\space m/s^{2}\) (magnitude of acceleration).

$$F=74\times150 = 11100\space N$$

Answer:

\(11100\)