Two basketball players are essentially equal in all respects. (they are the same height, they jump with the same initial velocity, etc.) in particular, by jumping they can raise their centers of mass the same vertical distance, (called h their "vertical leap"). the first player, arabella, wishes to shoot over the second player, boris, and for this she needs to be as high above boris as possible. arabella jumps at time , and boris jumps later, at time (his reaction time). assume that arabella has not yet reached her maximum height when boris jumps.

1)find the vertical displacement , d(t) = h(a)(t) - h(b)(t) as a function of time for the interval 0 < t < t(r) , where h(a)(t) is the height of the raised hands of arabella, while h(b)(t) is the height of the raised hands of boris.

express the vertical displacement in terms of h, g , and t.

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

(01.02 mc) nicole pushes her bike up a hill. overhead, the sun exerts a gravitational force on earth. which statement is true about the bike and earth? they both experience contact forces. they both experience non-contact forces. the bike experiences a non-contact force and earth experiences a contact force. the bike experiences a contact force and earth experiences a non-contact force. they both experience non-contact forces.

The voltage applied across a given parallel-plate capacitor is doubled. how is the energy stored in the capacitor affected?