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

Respuesta :

Hello!

Topic: Dinamic

Value to calculate: Force

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

[tex]\boxed{a=\frac{V-Vi}{t} }[/tex]

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:

[tex]a = \dfrac{29,16m/s-0m/s}{0,934s}[/tex]

[tex]a =31,22\ m/s^{2}[/tex]

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

[tex]\boxed{F=ma}[/tex]

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  

(1) The change in momentum of race car is 89880 kg-km/h.

(2) The average force exerted on the car is of 96231.26 N.

Given data:

The mass of race car is, m = 856 kg.

The initial speed of car is, u = 0 km/h.

The final speed of car is, v = 105 km/h.

The time interval is, t = 0.934 s.

1)

The change in the impact due to average force is known as momentum change. The expression for the change in momentum is given as follows,

[tex]\Delta P = m(v-u)[/tex]

Solving as,

[tex]\Delta P = 856 \times (105-0)\\\\\Delta P = 89880 \;\rm kg.km/h[/tex]

Thus, we can conclude that the change in momentum of race car is 89880 kg-km/h.

2)

Now, use the concept of impulse-momentum which says that the impulse is equal to change in momentum. Which means,

[tex]I = \Delta P[/tex]

And impulse is,

[tex]F \times t = \Delta P\\\\F = \dfrac{\Delta P}{t}[/tex]

Solving as,

[tex]F = \dfrac{89880}{0.934}\\\\F = 96231.26 \;\rm N[/tex]

Thus, we can conclude that the average force exerted on the car is of 96231.26 N.

Learn more about the impulse-momentum theorem here:

https://brainly.com/question/14121529