7) An Ice skater with her arms extended is rotating with initial kinetic energy Eki and has a moment of inertia I, then when she pulls her arms close to her body her moment of inertia goes down to 0.25 I. The final total kinetic energy (Ekf ) of the skater is A. Eki B. 2Eki C. 4Eki D. 16Eki E. Eki/4

50 g of ice at 0°c is dropped in a beaker containing 100 g of water at 0°c. what will be the contents of the beaker after 5 hours? assume that the room temperature is 0°c.

What is the average speed of a car that travels 40 mph for 1 hour and 60 mph in another hour?

Air is to be preheated by hot exhaust gases in a cross-flow heat exchanger before it enters the furnace. air enters the heat exchanger at 95 kpa and 20°c at a rate of 0.6 m^3/s. the combustion gases (cp = 1.10 kj/kg°c) enter at 160°c at a rate of 0.95 kg/s and leave at 95°c. determine the rate of heat transfer to the air and its outlet temperature.