Calvin is pulling Hobbes on his sled with a force of 45 N [30 degrees above the ground]. The mass of Hobbes and the sled is 18 kg and the coefficient of friction between the sled and the ground is 0.25.
What would the net force be in this case?
0?
Ws = M*g = 18 * 9.8 = 176.4 N.
Fn = 176.4 - 45*sin30 = Normal force.
Fk = u*Fn = Force of kinetic friction.
F(net) = 45*Cos30-Fk