Question

A car of mass 1000kg is moving at a speed of 20m/s.

It's brought to rest at a distance of 50m. Calculate the net force acting on the car. ​

Answer 1

-4000 N

Step-by-step explanation:

1. First let's look at what we know.

Mass: 1000 kg

Initial velocity: 20 m/s

Final velocity: 0 m/s

Displacement: 50 m

2. Let's try and apply a Kinematics equation here.

Looking at what information we have, I would say that this is the best equation:

v
`f^(2)`=v
`o^(2)` + 2aΔx

3. Plug in the numbers.

0 = 400 + 2(a)(50)

0 = 400 + 100a

-400 = 100a

a = -4 m/s^2

4. Use ∑F=ma

∑F = (1000)(-4)

∑F = -4000 N