In tae-kwon-do, a hand is slammed down onto a target at a speed of 10 m/s and comes to a stop during the 7.0 ms collision. Assume that during the impact the hand is independent of the arm and has a mass of 0.90 kg. What are the magnitudes of the (a) impulse and (b) average force on the hand from the target

Question

Autumn Brock

Physics

14 December, 17:05

In tae-kwon-do, a hand is slammed down onto a target at a speed of 10 m/s and comes to a stop during the 7.0 ms collision. Assume that during the impact the hand is independent of the arm and has a mass of 0.90 kg. What are the magnitudes of the (a) impulse and (b) average force on the hand from the target

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Answers (1)

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Maritza Johnston · Answer 1

(A) Impulse = 9Ns

(B) F = 1286N

Explanation:

Impulse = change in momentum = m (v-u)

v = 0 (the hand comes to a stop)

u = - 10m/s

Mass = 0.9kg

Impulse = 0.9 * (0 - (-10))

= 9Ns

(B) F*t = Impulse

F = Impulse / t

t = 7ms = 7*10-³

F = 9 / (7*10-³)

F = 1286N.