ten bricks each 6.0cm thick and mass of 1.5kg, lie on a table, how much work is required to stack them one on the top of another?

A. 40j
B. 88j
C. 45j
D. 0j
E. None of these

1 answer

original height of center of mass = 3 cm
final height of center of mass = 5^6 = 30cm
change in height of GC = 30-3 = 27 cm=.27m
work = m g h = 15 * 9.8 * .27 = 39.69 or 40 J so A