Answer: -5200 newtons
Your teacher may want you to type in just the positive version of this number.
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Step-by-step explanation:
We have these given values
- Vi = initial velocity = 28 m/s
- Vf = final velocity = 0, since we want the car to stop
- t = change in time = 10.5 seconds
The acceleration that occurs is....
a = (Vf - Vi)/t
a = (0 - 28)/10.5
a = -28/10.5
a = -2.66666666666667
This acceleration is approximate. The units for the acceleration are in m/s^2.
We'll use this acceleration value in Newton's Second Law equation
Force = (mass)*(acceleration)
F = m*a
F = (1950 kg)*(-2.66666666666667 m/s^2)
F = (1950*(-2.66666666666667)) kg m/s^2
F = -5200 newtons
The negative force value is to indicate the force is working against the car's original direction of motion. For instance, if the car is driving to the right, then a force to the left is applied as the braking force to slow the car down. It might be helpful to draw out the free body diagram.