Question

Please help I'm desperate. and please explain how need to show work!

Answer 1

Answer:

33.2 m/s

Explanation:

In order to solve this problem, we need to know the mass of the car.

Here, we assume that the mass of the car is

m = 1 kg

Then, we can apply the work-energy theorem, which states that the work done on the car by the braking force is equal to the change in its kinetic energy:

$W=\Delta E_k\\Fd=\frac{1}{2}mv^2-\frac{1}{2}mu^2$

where:

F = -3.87 N is the force applied by the brakes (negative because its direction is opposite to the motion of the car)

d = 4.92 m is the displacement of the car

u = 33.8 m/s is the initial velocity of the car

v is the final velocity of the car

Therefore, solving for v, we find:

$v=\sqrt{\frac{2Fd}{m}+u^2}=\sqrt{\frac{2(-3.87)(4.92)}{1}+(33.8)^2}=33.2 m/s$