Aptitude Test Problems in Physics Science for Everyone by S Krotov ( PDFDrive.com )

1. Mechanics 39

is known to act on the body at point A.

Determine the forces acting on the body

at points B and C.

Fig. 41

1.78. A conveyer belt having a length I

and carrying a block of mass m moves at a

velocity v (Fig. 41).

Determine the velocity vo with which the

block should be pushed against the direc-

tion of motion of the conveyer so that the

amount of heat liberated as a result of de-

celeration of the block by the conveyer belt

is maximum. What is the maximum amount

of heat Q if the coefficient of friction is IA

and the condition v < 17 - 4dg is satisfied?

1.79. A heavy pipe rolls from the same

height down two hills with different profiles

(Figs. 42 and 43). In the former case, the

Fig. 42 Fig. 43