An automobile of mass 2 000 kg moving at 30 m/s is braked suddenly with a constant braking force of 10 000 N.How far does the car travel before stopping?
A)45 m
B)90 m
C)135 m
D)180 m

Question

Quizplus · Accepted Answer

We can use the equation of motion that relates initial velocity, final velocity, acceleration, and distance traveled:

v^2 = u^2 + 2as

where v = 0 m/s (final velocity), u = 30 m/s (initial velocity), a = -5000 m/s^2 (braking acceleration, negative because it is in the opposite direction of motion), and s is the distance traveled before stopping.

Rearranging the equation, we have:

s = (v^2 - u^2) / 2a

Substituting the given values, we get:

s = (0 - 30^2) / (2 x (-5000)) = 90 m

Therefore, the car travels 90 m before stopping.

The best choice is B.

An Automobile of Mass 2 000 Kg Moving at 30