A bungee jumper of mass m jumps off a bridge. Assume that the bungee cord behaves like am ideal spring of spring constant k. When the jumper is at the lowest point in the motion that follows, the extension of the bungee cord is x.
After reaching the lowest point for the first time, the jumper rebounds straight upwards.
What is the magnitude of her velocity at the instant that the cord is at its natural length?

a) √(k/m) x
b)√[(kx²/m) - 2gx]
c) √(2gx)
d) √(-2gx)
e) None of the above

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?

What is the magnitude of the resultant vector round your answer to the nearest tenth

The earth is constantly spinning on its axis, like you might spin a basketball on your finger. it is this spinning of the earth that causes