A 450-kg sports car accelerates from rest to 100 km/h in 4.80 s.What is the magnitude of the net force exerted on a 68.0 kg passenger during the acceleration?
A)394 N
B)82.0 N
C)342 N
D)311 N

Question

Quizplus · Accepted Answer

First, convert the speed from km/h to m/s: $100 \, \text{km/h} = \frac{100 \times 1000}{3600} \, \text{m/s} = 27.78 \, \text{m/s}$. The acceleration $a$ can be calculated using the formula $a = \frac{\Delta v}{\Delta t}$, where $\Delta v = 27.78 \, \text{m/s}$ and $\Delta t = 4.80 \, \text{s}$, giving $a = \frac{27.78}{4.80} = 5.79 \, \text{m/s}^2$. The force exerted on the passenger can be found using Newton's second law, $F = ma$, where $m = 68.0 \, \text{kg}$ and $a = 5.79 \, \text{m/s}^2$, resulting in $F = 68.0 \times 5.79 = 393.72 \, \text{N}$, which rounds to $394 \, \text{N}$.

A 450-Kg Sports Car Accelerates from Rest to 100 Km/h