WAEC - Physics (1989 - No. 20)
A short chain is usual attached to the back of a petrol tanker trailing behind it to ensure that the
petrol tanker is balanced on the wh eel
heat generated by friction in the engine can be conducted to the floor
charges generated by friction in the tanker can be conducted to the earth
the tanker moves slowly as the chain touches the floor
chain produces sound for the resonance of the tanker engine