A sled loaded with bricks has a total mass of 17.0 kg and is pulled at constant speed by a rope inclined at 20.0o above the horizontal. The sled moves a distance of 17.0 m on a horizontal surface. The coefficient of kinetic friction between the sled and surface is 0.420 . (a) What is the tension in the rope?

1 answer

M*g = 17 * 9.8 = 166.6 N. = Wt. of the total mass.

Fn = 166.6*Cos 0 - T*sin20 = 166.6-0.342T = Normal force.

Fk = u*Fn = 0.420*(166.6-0.342T) = 70-0.144T Newton.

T*Cos20-Fk = M*a.
0.940T-(70-0.144T) = 17*0
0.94T-70+0.144T = 0
1.084T = 70
T = 64.6 N. = Tension in the rope.