(a) We know that work is the product of Force and Distance so: (in this
case Distance is negative since going down so –d)
work = force * distance
work = M * (g - g/4) * -d
work = -3Mgd/4
(b) The work by the weight of the block is simply:
work = Mgd
(c) The kinetic energy is simply equivalent to the
net work, therefore:
KE = net work
KE = Mgd/4
(d) The velocity is:
v = √(2*KE/M)
Plugging in the value of KE from c:
v = √(2*Mgd / 4M)
v = √(gd / 2)
