Place the ball in the plastic bag, and twist the top so the ball is secure in the bag. Wrap the twisted portion with tape so it stays tight. Use the hole punch or scissors to poke a hole in the part of the bag that’s above the ball. Slip an end of the string through the hole, and tie a knot. This is your pendulum. Hold the loose end of the string still with one hand. With the other hand, raise the ball in an arc so that it’s almost level with the hand holding the string. With the string taut, let the ball go. What do you observe?

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 causes the formation of ocean currents?

Explain what it means to view something from a frame of reference. provide an example that illustrates your explanation. (4 points)