ANICAL UNIVERSITY OF MOMBASA S 4101: PHYSICS VPHYSICS FOR ENGINEERSI CA
One
distance covered by a particle in time t is
-ct? + de, find the dimensions of a, b, cand d
osition of a particle at time t, is given by the
where is a constant and a>0. Find the
Y
26
s of v, and a
ertically upward projection, what is the velocity at th
locity of a body changes by the same amount for e
I, what can you say about the acceleration? 14 h
ilar spheres of equal mass with initial velocitjes 24
undergo an elastic collision. If Ug = 2 U2 = 20ms-
es after collision
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projection of 45°, how may the range be increased?
that for all projectiles except a freely falling one, the
bolic
a solid sphere moves through a liquid, the liquid op
with a force F. The magnitude of F depends on the
psity n, of the liquid, the radius r of the sphere and to
sphere. Assuming that F is proportional to different
nuantities, guess a formula for F using the​

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