Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Calculate the average power required by the electric motors

  1. Nov 5, 2005 #1
    I have three questions that I am pretty confused about:

    1. A slope rises 15m veritcally for every 40m of its length (in horizontal direction). A car of mass 1.25t travels a distance of 150m up the slope at uniform speed. Find the work done if the frictional resistance is 40N.

    2. A body of mass 0.3kg slides from rest down a plane inclined at 30 degrees to the horizontal. After sliding 30m down the plane it is found to have a speed of 10m/s. How much work has been done in overcoming friction along the plane?

    3. A Swiss mountain railway car of the rack and pinion type leaves Zermatt (1608m above sea level) at 9:30am and completes the 9km journey to the Gurnergrat (3136m above sea level) at 10:15am. If the car and the passengers together have a mass of 45t, calculate the average power required by the electric motors (neglect friction).
  2. jcsd
  3. Nov 5, 2005 #2


    User Avatar
    Homework Helper

    Please show what you've tried.
  4. Nov 7, 2005 #3
    Never mind! I solved them. :smile:
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook