Question

A 1000-kg car is driving toward the north along a straight horizontal road at a speed of 20.0 m/s. The driver applies the brakes and the car comes to a rest uniformly in a distance of 200 m. What are the magnitude and direction of the net force applied to the car to bring it to rest?

Answer 1

Answer:

Force will be acting southward and the magnitude of force will be 1000 N

Explanation:

given,

mass of car = 1000 Kg

initial speed of the car (u) = 20 m/s

final speed of the car (v) = 0 m/s

distance to stop the car = 200 m

using equation of motion

v² = u² + 2 a s

0 = 20² + 2 x a x 200

400 a = -400

a = -1 m/s²

Now, we know

Force = mass x acceleration

F = 1000 x -1

F = -1000 N

- ve sign of force represent force will be acting in the opposite direction of motion.

Force will be acting southward and the magnitude of force will be 1000 N