# physics

posted by .

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?

• physics -

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

• physics -

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

## Similar Questions

1. ### 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 …
2. ### 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 …
3. ### 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 …
4. ### 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 …
5. ### 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 …
6. ### 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 …
7. ### 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 …
8. ### 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 …
9. ### 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 …
10. ### Physics

A flat-topped 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 …

More Similar Questions