# physics

posted by
**Anonymous**
.

A 4.0-kg block is stacked on top of a 12.0-kg block, which is accelerating along a

horizontal table at a = 5.2m/s2 . Let u=uk=us.

(a) What minimum coefficient of friction u between the two blocks will prevent the 4.0-kg block

from sliding off?

(b) If u is only half this minimum value, what is the acceleration of the 4.0-kg block with respect to

the table?

(c) If u is only half this minimum value, what is the acceleration of the 4.0-kg block with respect to

the 12.0-kg block?

(d) What is the force that must be applied to the 12.0-kg block in (a) and in (b), assuming that the

table is frictionless?