While Felix and Jeff push a 57kg crate across a rough floor

While Felix and Jeff push a 57kg crate across a rough floor a 390N frictional force opposes its motion. If the crate has an acceleration of 0.45m/s2 and Jeff is pushing with a force of 265N, what is the strength of Felix\\\'s push?

Solution

Let strength of Felix\'s push be F

So,

acceleration,a=0.45 m/s^2

mass of crate,m=57 kg

Friction,f=390 N

Jeff\'s pushing force, J=265 N

So we have by Newton\'s third law of motion

ma= J+F-f

57*0.45=265+F-390

F=150.65 N