A cart loaded with bricks has a total mass of 17 kg and is pulled at constant sp

Question

A cart loaded with bricks has a total mass of 17 kg and is pulled at constant speed by a rope. The rope is inclined at 25 degrees above the horizontal and the cart moves 22.8 m on a horizontal floor. The coefficient of kinetic friction between ground and cart is 0.6. The acceleration of gravity is 9.8 m/s^2.

a. What is the normal force exerted on the cart by the floor? Answer in units of N.

b. How much work is done on the cart by the rope? Answer in kJ

c. Note: The energy change due to friction is a loss of energy. What is the energy change Wf due to friction ? Answer in kJ.

Explanation / Answer

Total mass of crate m = 17 Kg

Distance moved S = 22.8 m

Coefficient of Kinetic friction = 0.6

Angle = 25 degrees

(a)

Normal force R = mg - T sin

and T cos = R

      T cos25 = 0.6[(17*9.8) - T sin25]

      0.906 T = 99.96 - 0.253 T

         1.159 T = 99.96

                  T = 86.2 N

Normal force R = 166.6 - 36.429 = 130.17 N

(b)

Work done by rope W1 = T S cos = 86.2 * 22.8 * cos25 = 1.781 KJ

(c)

Energy change due to friction W2 = - RS = - 1.78 KJ

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.