physics
posted by phys1! .
A cart loaded with bricks has a total mass
of 18 kg and is pulled at constant speed by
a rope. The rope is inclined at 30.4 above
the horizontal and the cart moves 21.5 m on
a horizontal floor. The coefficient of kinetic
friction between ground and cart is 0.8 .
The acceleration of gravity is 9.8 m/s2 .
How much work is done on the cart by the
rope?
Answer in units of kJ

Calculate the rope tension from the information given.
Call it T.
The horizontal component of T = Friction force
since it does not accelerate.
(M*g  T sin21.5) *0.8 = T cos 21.5
Solve for T
Work done by rope = T*cos30.4*21.5 m 
T*cos(θ) = Ffr –––> Ffr = µk* Fn –––>
Fn = m*g  T*sin(θ) :
T*cos(θ) = ( µk*(m*g  T*sin(θ) )
T*cos(30.4º) = (0.8 *(18*9.8 – T*sin(30.4º))
T*cos(30.4º) = 88.2 N – 0.8 * T *sin(30.4º)
T*cos(30.4º) + 0.8*T*sin(30.4º) = 141.12 N
T (cos(30.4º) + 0.8*sin(30.4º)) = 141.12 N
T = 141.12 N / (cos(30.4º) + 0.8*sin(30.4º))
T = 111.4 N

Work = T*cos(θ)*d
W = 111.4*cos(30.4º)*21.5m = 2065.81 J or 2.07 kJ
Respond to this Question
Similar Questions

Physics
Three part problem cant figure out the second and third parts (part 1 of 3) A cart loaded with bricks has a total mass of 12.9 kg and is pulled at constant speed by a rope. The rope is inclined at 20.6 ◦ above the horizontal … 
Physics
A cart loaded with bricks has a total mass of 28.5 kg and is pulled at constant speed by a rope. The rope is inclined at 28.1 ◦ above the horizontal and the cart moves 13.9 m on a horizontal floor. The coefficient of kinetic … 
physics
A cart loaded with bricks has a total mass of 27.7 kg and is pulled at constant speed by a rope. The rope is inclined at 23.7 ◦ above the horizontal and the cart moves 23.1 m on a horizontal ﬂoor. The coeﬃcient … 
physics
A cart loaded with bricks has a total mass of 13.5 kg and is pulled at constant speed by a rope.The rope is inclined at 27.9 degrees above the horizontal and the cart moves 13mts on a horizontal floor.The co efficient of kinetic friction … 
Physics!!
A cart loaded with bricks has a total mass of 25.2 kg and is pulled at constant speed by a rope. The rope is inclined at 21.6 ◦ above the horizontal and the cart moves 13.7 m on a horizontal floor. The coefficient of kinetic … 
physics
A sled loaded with bricks has a total mass of 18.0 kg and is pulled at constant speed by a rope inclined at 30.0o above the horizontal. The sledge moves a distance of 16.0 m on a horizontal surface. The coefficient of kinetic friction … 
Physics
A cart loaded with bricks has a total mass of 25.4 kg and is pulled at constant speed by a rope. The rope is inclined at 30.6 ◦ above the horizontal and the cart moves 18.4 m on a horizontal ﬂoor. The coeﬃcient … 
Physics
A cart loaded with bricks has a total mass of 22.3 kg and is pulled at constant speed by a rope. The rope is inclined at 27.3◦ degrees above the horizontal and the cart moves 9.3 m on a horizontal surface. The coefficient of … 
Physics
A cart loaded with bricks has a total mass of 22.3 kg and is pulled at constant speed by a rope. The rope is inclined at 27.3◦degrees above the horizontal and the cart moves 9.3 m on a horizontal surface. The coefficient of kinetic … 
Physics
A flattopped toy cart moves on frictionless wheels, pulled by a rope under tension T. The mass of the cart is m1. A load of mass m2 rests on top of the cart with the coefficient of static friction μs between the cart and the …