College physics

posted by .

Consider the two situations. In the first a machine must pull a box up a rough slope at constant speed. The mass of the box is 800 kg, the coefficient of kinetic friction is 0.2, and the slope is inclined at 15 degrees to the horizontal. In the second situation the machine must pull an equally massive wheel up the same slope. The cable is attached to the axle of the wheel and exerts negligible torque about the axis. If both the box and the wheel move up the slope at 0.5 m/s then how much power (in Watts) must the machine supply for each task?

  • College physics -

    Sliding box:
    Power = (Friction force + Weight component up ramp) x velocity
    = (M*g*cos15*0.2 + M*g*sin15)*V
    = (800*9.8)(0.1932 +0.2588)*0.5
    = 1772 W

    Wheel:
    Power = (Weight component up ramp) x velocity
    component up ramp) x velocity
    = (M*g*sin15)*V
    = (800*9.8)(0.2588)*0.5
    = 1015 W

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Physics

    What value of F can pull the 5.00 kg box at constant velocity up the incline if uk=0.25. u means coeffiient friction the angle is 30 degrees and 5.00 kg force is going up Break up the weight of the box into two components: Perpendicular …
  2. physics

    A box is placed on a conveyor belt that moves with a constant speed of 1.05 m/s . The coefficient of kinetic friction between the box and the belt is 0.800. How much time does it take for the box to stop sliding relative to the belt?
  3. Physics

    A box with a mass of 7.00 kg is at rest on a ramp that is at an angle of 20 degrees with the horizontal. The coefficient of static friction between the box and the ramp is 0.800. Use g = 9.80 m/s2. You now want to make the box move …
  4. Physics

    At the beginning of a new school term, a student moves a box of books by attaching a rope to the box and pulling with a force of 92 N at an angle of 30 as shown in the figure below. The box of books has a mass of 22.0 kg, and the coefficient …
  5. physics

    A box of unknown mass is sliding with an initial speed vi = 5.60 m/s across a horizontal frictionless warehouse floor when it encounters a rough section of flooring d = 3.40 m long. The coefficient of kinetic friction between the rough …
  6. physics

    You are a member of an alpine rescue team and must get a box of supplies, with mass 3.00kg , up an incline of constant slope angle 30.0∘ so that it reaches a stranded skier who is a vertical distance 2.90m above the bottom of …
  7. physics

    Joe pushes horizontally on a heavy box across a rough surface at constant speed. Which one of the following statements concerning this situation is false?
  8. PHYSICS 1301 (COLLEGE)

    A box of unknown mass is sliding with an initial speed vi = 5.10 m/s across a horizontal frictionless warehouse floor when it encounters a rough section of flooring d = 4.20 m long. The coefficient of kinetic friction between the rough …
  9. Physics

    A box of unknown mass is sliding with an initial speed vi = 5.40 m/s across a horizontal friction-less warehouse floor when it encounters a rough section of flooring d = 3.50 m long. The coefficient of kinetic friction between the …
  10. physics

    1. A 50.0 Lb box is to be moved along a rough floor at a constant velocity. The coefficient of the kinetic friction is 0.300. A. What force must you exert if you push downward on the box?

More Similar Questions