11)A 1100 kg car travels on a straight highway with a speed of 30 m/s. The driver sees a red light ahead and applies her brakes, which exert a constant braking force of 4000N. In how many seconds will the car stop?

The time taken by the car to stop is 8.26 s.

Given data:

The mass of car is, m = 1100 kg.

The speed of car is, u = 30 m/s.

The magnitude of braking force is, F = 4000 N.

We need to first obtain the acceleration of car to get that, apply the Newton's second law as,

F = - ma    (Negative sign shows that the force will resist the motion)

4000 = -(1100) a

Now, apply the first kinematic equation of motion to obtain the time taken by the car to stop as,

v = u + at

Here, v is the final speed and v = 0, since car will stop finally.

So,

Thus , we can conclude that the time taken by the car to stop is 8.26 s.

Learn more about the Newton's second law of motion here:

link

Time taken = 8.25 second

Explanation:

Given:

Force = 4000 N

Force = ma

4,000 = (1100)(a)

Acceleration = 3.6363 m/s²

v = u + at

0 = 30 + (3.6363)t

Time taken = 8.25 second

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