Question

An 856 kg drag race car accelerates from rest to 105 km/h in .934s. What change in momentum does the force produce? Answer in units of kg • m/s
Part 2: what average force is exerted on the car? Answer in N

Answer 1

Hello!

Topic: Dinamic

Value to calculate: Force

First, we have to calculate the aceleration, for that, lets aplicate the formula:

$\boxed{a=\frac{V-Vi}{t} }$

How the final velocity is in km/h, we have to convert it on m/s, so:

m/s = km/h / 3,6

m/s = 105 / 3,6

m/s = 29,16

Then, lets replace formula according problem information:

$a = \dfrac{29,16m/s-0m/s}{0,934s}$

$a =31,22\ m/s^{2}$

Now, how we have the aceleration, lets applicate second law of newton for calculate the force produced:

$\boxed{F=ma}$

Replace and resolve it:

F = 856 kg * 31,22 m/s^2

F = 26724,32 kg * m/s^2

Then the force is of 26724,32 kg * m/s^2

But how we know an 1 kg * m/s^2 = 1 N

Then the average of the force is of 26724,32 N