XA Problem statement: The mass-pulley Data & Diagram: (Draw and label completely)
system is designed to consist of log A, block
B, and collar D as shown. Given that both
log A and collar D move with a constant
acceleration of 0.2g downward (g=9.81 m/s)
and that the system starts from rest,
determine
Find;
B
XD
(a) the acceleration of block B at this
instant,
(b) the corresponding acceleration of collar
D
D relative to block B, and
A
[+2]
(c) the velocity of log A after it has
displaced 10 cm, the corresponding
time, and displacement of block B.
Assumption(s);
Theory:
1. Cable or rope remains taut. [+ 1]
Kinematics relation; [1]
2. All frictional effects are negligible.
Length of cable = constant

Acommercial grade cubical freezer, 4 m on a side, has a composite wall consisting of an exterior sheet of 5.0-mm thick plain carbon steel (kst= 60.5 w/m k), an intermediate layer of 100-mm thick polyurethane insulation (kins 0.02 w/m k), and an inner sheet of 5.0- mm thick aluminium alloy (kal polyurethane insulation and both metallic sheets are each characterized by a thermal contact resistance of r 2.5 x 104 m2 k/w. (a) what is the steady-state cooling load that must be maintained by the refrigerator under conditions for which the outer and inner surface temperatures are 25°c and -5°c, respectively? (b) for power saving purpose, which wall material should be increased/reduced in. thickness in order to reduce 50% of the cooling load found in part (a)? redesign the thickness of the proposed material. 177 w/m-k). adhesive interfaces between the q=575.93 w