An automobile accelerates from rest at 2.0 m/s2 for 20 s. The speed is then held constant for 20 s, after which there is an ac- celeration of -3.0 m/s? until the automobile stops. What is the total distance traveled?

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?

How long will a plane have to fly continuously with 1100 miles per hour in order to cover the same distance as that from earth to the next star, proxima centauri?

In the graph, each sinusoidal curve shows the shape of a vibrating string at a different moment. for which values of x does a node occur? (let k = an integer from -2 to +2.) k + 0.5 0.5k k 2k + 1.5