Question

An object weighing 72 newtons is being accelerated at 3.5 m/s^2 by an unknown force Fp at an angle of 35 degrees from the horizontal. The object is being pushed across a surface with a coefficient of friction 0.2. Find Fp.

Answer 1

mass = 72/g = 72/9.81 = 7.34 kg
horizontal component F = Fp cos 35 = .819 Fp
force down = Fp sin 35 + m g
= .574 Fp + 72
friction force = .2(.574 Fp+72)
so
7.34 (3.5) = .819 Fp - .2(.574 Fp + 72)