Question

ok part (b)

A 4.0 kg block is stacked on top of a 12.0 kg block, whcih is accelerating along a horizontal table at a = 5.2 s^-2 m. Let Mu k = Mu s = Mu.

(a) What mininum coefficent of friction Mu between the two blocks will prevent the 4.0 kg block from sliding off?

(b) If Mu is only half this mininium vale, what is the acceleration of the 4.0 kg block with respect to the table, and

(c) 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?

for (a) I got .66

ok for (b) I got 3.2 s^-2 m

for (c) I got 2.0 s^-2 m

And I don't understand what the problem means by

"(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?"

Does this mean that for (a) the bottom block experiances a force of kinetic friction were Mu is the same Mu i found in part(a) of .66????

part (b) is frictionless with the table... I know how to do that just don't understand what the other part is asking??????

Answer 1

Sense this problem 32 the answer isn't in the back =[

Answer 2

can you check my answer for (c)

Answer 3

ok for the applied force for (a) on the bottom block I got 83 N not sure if it's right...

for the applied force in (b) wouldn't it be the same... I'm confused...

Can you check my answer for (c)

Answer 4

The bottom block has no friction with the table.

If you know the acceleration, then the force applied must be (totalmass)a where totalmass is 12+4 kg.