How does the moon's gravitational pull on earth compare with earth's gravitational pull on the moon?
a. the moon pulls with more gravitational force.
b. earth pulls with more gravitational force.
c. because both earth and the moon go around the sun, there is no gravitational force between earth and the moon.
d. the gravitational pull of earth on the moon is the same as the gravitational pull of the moon on earth.

Six solutions are made, each with a y concentration of 1.0 μm and varying concentrations of ab as shown below. based on the concentrations, rank the solutions in decreasing order of reaction rate.

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?

If 21.2 kcals of energy is released by this reaction, how many kj does the reaction release? (1 cal 4.184 j)