1. PF Contest - Win "Conquering the Physics GRE" book! Click Here to Enter
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Tractive motion, with gradients, Hard questions

  1. May 12, 2009 #1
    tractive motion, with gradients, Hard questions!!

    4.1 An engine mass of 95 tonnes is hauling a train of mass 750 tonnes along a section of level track. the tractive resistance to motion of the engine is 120 N/tonne and the rolling resistance for the train is 90 N/tonne. initially the engine is travelling at 27 km/hr and then it accelerates over a distance of 1500m.

    A) Calculate the power required to achieve this increase in speed?
    B)The train then meets a downgrade of 1V in 110H and is brought to a stop in a distance of 900m. calculate the braking force required to stop the train?

    4.7 A large truck mass of 35 tonnes is traveling down a gradient of 1V in 60H at a speed of 90 km/hr. The rolling resitance to motion is 115 N tonne.

    A) If when the brakes are applied the truck is brought to a stop in 400m what is the applied braking force?
    B)How much power is required to provide this braking force?
    C)If this same power were available on a uphill gradient of 1 in 60 what constant speed would the truck be capable of reaching?

    If u cannot convert km/hr in2 metres per second (ms-1) its (km/hr X 1000) /3600
  2. jcsd
  3. May 12, 2009 #2


    User Avatar
    Science Advisor
    Homework Helper

    Welcome to PF!

    Hi paul7776! Welcome to PF! :wink:

    Show us what you've tried, and where you're stuck, and then we'll know how to help! :smile:
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Threads - Tractive motion gradients Date
Average Force Question Given Velocities [High School] Tuesday at 7:33 PM
Tractive Force Jun 12, 2017
Tractive Force Train Nov 15, 2011
Equilibrium in a tractive apparatus - tension and pulleys Jan 31, 2010
Tractive force Apr 27, 2008