1 Answer

Alexander Sorkin · Answer 1 · 2023-07-21T13:30:11+0000

According to Newton's Second Law of Motion, the net force acting over an object is responsible for the acceleration of the object:

$\Sigma F=ma$

Since the friction and the horizontal force act in opposite directions, then:

$\Sigma F=F_H-f$

Where F_H represents the horizontal force and f represents the friction.

Replace the expression for the net force and isolate f:

$\begin{gathered} F_H-f=ma \\ \Rightarrow f=F_H-ma \end{gathered}$

To find the magnitude of the friction, replace F_H=89.7N, m=22.5kg and a=1.23m/s^2:

$\begin{gathered} \Rightarrow f=(89.7N)-(22.5\operatorname{kg})(1.23(m)/(s^2)) \\ =89.7N-27.675N \\ =62.025N \\ \approx62.0N \end{gathered}$

Therefore, the magnitude of the force of kinetic friction acting on the crate is 62.0 N.

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