Question

a person pushes a box across the floor with a force of 75 n. the box accelerates at a rate of 2m/s^2. the mass of the box is 25 kg. what is the magnitude of the force of friction?

Explanation:

Step1: Apply Newton's second law

$F_{net}=ma$

Step2: Define net - force

$F_{net}=F_{applied}-F_{friction}$

Step3: Substitute and solve for friction force

$F_{applied}-F_{friction}=ma$
$75 - F_{friction}=25\times2$
$75 - F_{friction}=50$
$F_{friction}=75 - 50$

Answer:

$25\ N$