1) a 2000 kg car is traveling at 30 m/s on a level road .

a) what is the car's kinetic energy ?
b) what is the car's potential energy ?
c) what is the car's mechanical energy ?

2) mark has a mass of 55 kg and climbs up a short, steep trail of length 300 m to reach the top of a 100 m tall cliff. matthew , his twin brother, walks up a gentle, winding trail of length 500 m to reach the top of the same cliff. what is the potential energy of each boy at the top?

3- death valley, california , has an elevation of 86 meters below sea level. what is the potential energy of a 60 kg teacher in death valley?

Foreshadowing. the prologue states that this is the story of "star-crossed lovers." there are four strong foreshadowings of evil in act 1. identify at least two foreshadowings and explain their purpose.

An internally reversible refrigerator has a modified coefficient of performance accounting for realistic heat transfer processes of where qin is the refrigerator cooling rate, qout is the heat rejection rate, and is the power input. show that copm can be expressed in terms of the reservoir temperatures tc and th, the cold and hot thermal resistances rt,c and rt,h, and qin, as where rtot rt,c rt,h. also, show that the power input may be expressed as 1.39 a household refrigerator operates with cold- and hot-temperature reservoirs of tc 5 c and th 25 c, respectively. when new, the cold and hot side resistances are rc,n 0.05 k/w and rh,n 0.04 k/w, respectively. over time, dust accumulates on the refrigerator’s condenser coil, which is located behind the refrigerator, increasing the hot side resistance to rh,d 0.1 k/w. it is desired to have a refrigerator cooling rate of qin 750 w. using the results of problem 1.38, determine the modified coefficient of performance and the required power input w under (a) clean and (b) dusty coil conditions. internally reversible refrigerator qout qin w high-temperature reservoir low-temperature reservoir th th,i tc,i tc high-temperature side resistance low-temperature side resistance w qin th tc qinrtot tc qinrtot copm tc qinrtot th tc

An object in mechanical equilibrium is an object