For a locomotive of mass hauling a train on level track
PHYSICS · Multi-part · CBSE · Physics · Work, Energy and Power · Work, Energy and Power
Problem
For a locomotive of mass 2.0×105kg hauling a train on level track, the mechanical power output of the engine varies with its speed according to P=kv, where k=4.0×105Wsm−1. No other horizontal forces act on the locomotive–train system.
(i) Express the horizontal tractive force exerted by the wheels on the track in terms of k and v.
(ii) Form the differential equation linking the acceleration of the train to its speed and hence obtain a formula for the speed v(t) when the train starts from rest at t=0.
(iii) Calculate the speed after 60s.
(iv) Determine the distance travelled in the first 60s.