How long will it take a force of 10 N to stop a mass of 2.5 kg which is moving at 20 m/s?

Force applied (F) = -10 N (since the force is acting in the opposite direction of motion or opposing the motion)

Mass of body (m) = 2.5kg


Initial velocity of body (u) = 20m/s


Final velocity of body (v) = 0m/s


According to Newton's second law of motion


F = ma


-10 = 2.5×a


-10/2.5 = v-u/t (since a = v-u/t)


-4t = 0 - 20


t = -20/-4


t = 5 sec


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