What is the efficiency of a device that takes in 40,000 j of heat and does 12,000 j of work while giving off 28,000 j of heat? use and convert to a percentage. a.70% b. 57% c. 30% d. 43%

Air flows upward in the wick of a lantern because of the liquid property called

Which is the best for showing percentages of different types of cars sold(gas hybrid , electric , other ) in the united states ?

Askydiver weighing 140 lb (including equipment) falls vertically downward from an altitude of 19,000 ft and opens the parachute after 18 s of free fall. assume that the force of air resistance, which is directed opposite to the velocity, is of magnitude 0.55|v| when the parachute is closed and is of magnitude 14|v| when the parachute is open, where the velocity v is measured in ft/s. assume that acceleration due to gravity has magnitude 32 ft/s/s; remember that weight is the product of mass and gravitational acceleration. (a) find the speed of the skydiver when the parachute opens. (b) find the distance fallen before the parachute opens. (c) what is the limiting velocity vl after the parachute opens? (d) determine how long the sky diver is in the air after the parachute opens. (e) plot the graph of velocity versus time from the beginning of the fall until the skydiver reaches the ground.