As part of a project for his biology class, Alex is studying the motion of a turtle over the course of an hour. He places the turtle at the center of a
circular tank. After a few minutes, the turtle hasn't moved and Alex ends up
drifting off to sleep. When Alex wakes up at the end of the hour, the turtle is
still at the center of the tank. Which of the following can Alex conclude about
the turtle's motion during the hour?

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?

Why are graphs useful when interpreting data

Aplane flying horizontally at an altitude of 1 mile and a speed of of 500mih passes directly over a radar station. find the rate at which the distance from the plane to the station is increasing when it is 2mi away from the station.