A 10-kilogram block with an initial velocity of 10 m/s slides 10 meters across a horizontal surface and comes to rest. It takes the block 2 seconds to stop. The stopping force acting on the block is about
A)5 N.
B)10 N.
C)25 N.
D)50 N.
E)none of the above

Question

Quizplus · Accepted Answer

The stopping force can be calculated using the formula F = ma, where m is the mass and a is the acceleration. First, find the acceleration using the formula a = (v_f - v_i) / t, where v_f is the final velocity (0 m/s), v_i is the initial velocity (10 m/s), and t is the time (2 s). This gives a = (0 - 10) / 2 = -5 m/s^2. The negative sign indicates deceleration. Then, F = (10 kg)(-5 m/s^2) = -50 N. The negative sign indicates the direction of the force is opposite to the motion, but the magnitude of the force is 50 N.

A 10-Kilogram Block with an Initial Velocity of 10 M/s