Question

A person with a black belt in taekwondo has a foot with a mass of 0.90 kg. Starting from rest, this foot attains a velocity of 8.3 m/s in 0.13 s. What is the magnitude of the average net force applied to the foot to obtain that acceleration?

Answer 1

57.42 N

Step-by-step explanation:

We first find the acceleration knowing that it goes from rest to 8.3 m/s in 0.13 seconds,

Therefore, the acceleration is:

`a=(v_f-v_i)/(time) =(8.3-0)/(0.13 ) =63.8\,\,m/s^2`

Now we use this to calculate the average net force by multiplying mass times acceleration:

F = m * a = 0.9 (63.8) = 57.42 N