The picture is not complete.
Are the two blocks identical (in mass) ?
Does block B hang free?
If it is, B will descend as A moves up.
Draw the free body diagram of each block.
Let the tension in string be T.
mass of each block = m
acceleration due to gravity = g
angle of incline = θ = 30°
Distance moved = s = 4m
Change in potential energy of system, δep
mgs(sinθ)-mgs
=mgs(sinθ-1)
Assuming no frictional and air-resistance loss,
δep+δek=0, or
δek=mgs(1-sinθ)
Equate δek to (1/2)(m+m)v² to solve for v.
Two blocks A and B are connected by a light in extensible cord passing over a frictionless pulley. Block A starts from rest and moves up the smooth plane which is inclined at 30 degrees to the horizontal. Calculate at the moment that A has moved 4 m along the plane.
(a) the total kinetic energy of the system
(b) the speed of the blocks A and B
1 answer
1 answer