Solving Interaction Forces Physics Problem: Magnitude & Direction

[LaShortiie]

Okay i have a physics problem that i really don't get...pliz help me!

A 6.0-kg block rests on top of a 7.0-kg, which rests on a horizontal table.

a What is the force (magnitude and direction) exerted by the 7.0-kg block on the 6.0-kg block?

i tried using the formula F sub a and b = F sub b and a
but my book really doesn't explain how to work out the problem...help!

bWhat is the force (magnitude and direction) exerted by the 6.0-kg block on the 7.0-kg block?

 

[Doc Al]

First, what can you say about those two forces? (Consider Newton's 3rd law.)

Second, consider all the forces acting on the top block. (What are they? Hint: There are two forces acting.) What must they add up to?

 

[LaShortiie]

I think that its gravity that is acting on the top block but i don't know what else

 

[Hootenanny]

I think that its gravity that is acting on the top block but i don't know what else

What would happen to the 6kg block if the only force acting was gravity?

 

[LaShortiie]

it would put more force on the table? could the other force be either mass or friction?

 

[Doc Al]

I think that its gravity that is acting on the top block but i don't know what else

Since you are asked to find the force that the bottom block exerts on the top block (that's part a), that should tell you something! That's the second force acting on the top block.

 

[LaShortiie]

Its in the table pushing up the bottom block upwards so the other force would be the table