This question is typical on some driver's li-
cense exams: a car moving at 50 km/h skids
15 m with locked brakes.
how far will the car skid with locked brakes
at 125 km/h? assume that energy loss is due
only to sliding friction.
answer in units of m.

Acar accelerates from 5.0 m/s to to 11 m/s at a rate of 3.0 m/s^2. how far does it travel while accelerating? 20m 117m 43m 16m

Why do electron microscopes have higher resolving power than light microscopes?

Acoal-fired plant generates 600 mw of electric power. the plant uses 4.8 x 10^6 kg of coal each day, and the heat of combustion of coal is 3.3x 10^7 j/kg. the steam that drives the turbines is at a temperature of 300° c, and the exhaust water is at 37° c. (a) what is the overall efficiency of the plant for generating electric power? (b) how much thermal energy is exhausted each day? (c) what is the change in entropy of the universe for this heat engine? (d) using the same heat reservoirs, what is the maximum possible (carnot) efficiency for a heat engine?