148k views
3 votes
This is the last question that I need help with, and I'll try and do the rest on my own. Thank you to all of the tutors that helped me with this!

This is the last question that I need help with, and I'll try and do the rest on my-example-1
User AyKarsi
by
2.9k points

1 Answer

6 votes

Question 7.

Given:

Mass, m = 2200 kg

Time, t = 8 s

Velocity = 12 m/s

Let's find the average net force required to stop the car.

To find the average net force required to stop the car, let's first find the acceleration of the car.


v=v_o+at

Where:

Initial velocity, vo = 12 m/s

Final velocity, v = 0 m/s (velocity of car when it stops)

t is the time = 8 seconds

a is the acceleration.

Rewrite the formula for a:


a=(v-v_o)/(t)

Hence, we have:


\begin{gathered} a=(0-12)/(8) \\ \\ a=(-12)/(8) \\ \\ a=-1.5m/s^2 \end{gathered}

The acceleration is -1.5 m/s² (negative because the car is deccelerating).

Now, to find the net force, we have:


\sum ^{}_{}F=ma

Where:

m is the mass = 2200 kg

a is the acceleration = -1.5 m/s²

Hence, we have:


\sum ^{}_{}F=2200*(-1.5)=-3300\text{ N}

The negative sign indicates that the force acts in the opposite direction the car is travelling.

Therefore, average net force required to stop the car is 3300 Newtons in the opposite direction.

ANSWER:

3300 N in the opposite direction

User TobiX
by
3.4k points