Physics- Elena please help!

A sled loaded with bricks has a total mass of 18.0 kg and is pulled at constant speed by a rope inclined at 40.0o above the horizontal. The sledge moves a distance of 16.0 m on a horizontal surface. The coefficient of kinetic friction between the sledge and surface is 0.510 .
(a) What is the tension in the rope?
b) How much work is done by the rope on the sled?
c)What is the magnitude of the force of friction?
(d) What is the mechanical energy lost due to friction?

  1. 👍
  2. 👎
  3. 👁
  4. ℹ️
  5. 🚩
  1. force pulling sled = T cos 40
    force lifting sled = T sin 30

    normal force = mg - T sin 40
    friction force = 0.51(mg - T sin 40)

    acceleration = 0
    so
    friction force = pulling force
    so
    0.51(mg - T sin 40) = T cos 40
    solve for T

    then work = 16 * T cos 40

    etc

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
  2. Can you tell me the values you are getting so I can make sure I did the algebra right?

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
  3. How about the other way around? You post the values and I check. I already took the course (in 1955).

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
  4. For Tension I am getting 117.4

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
  5. m g = 177 N

    .51 (177 - .643 T) = .766 T

    90.3 - .328 T = .766 T

    T = 82.5 N

    T cos 40 = 63.2 = pull force = friction force
    63.2 * 16 = 1012 Joules = work done (also energy lost to friction)

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
  6. What is the label for the work? I tried Newtons and that is wrong.

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
  7. Work is in Joules !!!!

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
  8. work done against friction = ENERGY lost
    That is JOULES !

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
  9. Oh ya, I understand part a and b now, but I am still confused on part c. How would I solve this?

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
  10. We did part C immediately

    T cos 40 = 63.2 = pull force = friction force

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
  11. It is not accelerating so friction force is equal and opposite to pulling force.

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
  12. Now slow down and draw a good picture and follow what I did carefully step by step. I have to go coach a high school sailing team now.

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩

Respond to this Question

First Name

Your Response

Similar Questions

  1. physics

    A 17-kg sled is being pulled along the horizontal snow-covered ground by a horizontal force of 29 N. Starting from rest, the sled attains a speed of 2.1 m/s in 9.6 m. Find the coefficient of kinetic friction between the runners of

  2. Physics

    A loaded penguin sled weighing 60 N rests on a plane inclined at 20° to the horizontal. Between the sled and the plane the coefficient of static friction is 0.27, and the coefficient of kinetic friction is 0.13. (a) What is the

  3. Science

    A sled is at rest at the top of a 2 m high slope. The sled has a mass of 45 kg. What is the sled's potential energy?

  4. physics

    A loaded dogsled has a mass of 400kg and is being pulled across a horizontal, paced snow surface at a velocity of 4.0m/s (N). Suddenly, the harness separates from the sled. If the coefficient of kinetic friction for the sled on

  1. physics

    Suppose the ski patrol lowers a rescue sled and victim, having a total mass of 95.0 kg, down a θ = 50.0° slope at constant speed. The coefficient of friction between the sled and the snow is 0.100. (a) How much work is done by

  2. physics

    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

  3. Physics

    A father pushes horizontally on his daughter's sled to move it up a snowy incline, as illustrated in the figure, with h = 3.9 m and θ = 11°. The total mass of the sled and the girl is 35 kg and the coefficient of kinetic

  4. physics

    A sled is accelerating down a hill at a rate of 1 m/s2 . If the mass of the sled is suddenly cut in half and the net force on the sled is doubled, what is the acceleration of the sled?

  1. physics

    a 12 kg sled is pulled horizontally with a force of 82 N. the coefficent of the kentic friction of the sled is 0.42. draw a FBD of the sled.

  2. math

    a flatbed truck is loaded with 7000 pounds of bricks . how many tons of brick are loaded on the truck

  3. Physics

    Josh pulls a sled with a force of 100-N at an angle 30° above horizontal axis. The total mass of the sled and Josh’s sister is 60.0-kg. The friction coefficient between the surface and the sled:static= 0.160; kinetic= 0.100 a)

  4. science

    The expression like a ton of bricks means “a crushing weight.” Would being hit by an actual ton of bricks hurt if it happened on the moon? A) Yes, it would hurt because the bricks would still have the same weight. B) Yes, it

View more similar questions or ask a new question.