Why is the acceleration the same for block on block?
Answers
Consider two blocks, one on top of the other on a frictionless table, with masses m1 and m2 respectively. There is appreciable friction between the blocks, with coefficients μs and μk for static and kinetic respectively. I'm considering the fairly routine problem of determining the maximum horizontal force F (say, to the right) that can be applied to the top block so that the two blocks accelerate together.
The problem is not hard to solve symbolically. If the two blocks move together, their accelerations are the same, and the top block doesn't move with respect to the bottom block, so only static friction is in play. In a standard coordinate system (with x oriented to the right), the sum of horizontal forces for the top block is
F−Fsf=m1a
and for the bottom block
Fsf=m2a
where Fsf is the force of static friction. Solving for a in these two expressions, and then equating them, gives
F=(m1+m2)Fsfm2
The maximum such force will therefore be achieved when Fsf is maxed out at μsm1g, so
Fmax=m1m2μs(m1+m2)g
Answer:
let you place blocks(as much as u can) side by side on a frictionless incline plane with inclination of theta with horizon.so for each block acceleration component along the incline plane is (g sin theta).and there is no frictionless force that means the blocks will move together just for the acceleration and the normal force between 2 blocks will be zero.
even it is applicable for horizontal surface.
if you keep some blocks on the surface and apply a force from any side the blocks will move with same acceleration because there is no opposing force as the surface is smooth