Cody A block of mass m starts at rest at the position shown on an inclined plan.
ID: 1331515 • Letter: C
Question
Cody A block of mass m starts at rest at the position shown on an inclined plan. (The angle theta is known.) a. If there is no friction, what horizontal force must be applied to the block in order for it to remain at rest? if there were a coefficient of friction n between the block and the plane, what is the smallest horizontal force that could be applied to the block and have the block move up the plane? (Essentially zero acceleration up the plane.) If there were a coefficient of friction n between the block and the plane, what is the largest horizontal force that could be applied to the block and have the block move down the plane? Essentially zero acceleration down the plane.)Explanation / Answer
(a)when at friction is zero then
the block is at rest only at upward force is equal to downward force which is
F=mgcos(teeta)
(b) when friction is added then
F=mgcos(teeta)-Un*N
where Un is frictional constant and N is normal force
then it moves upward when
mgcos(teeta)-Un*N>F
(c)
it moves downward to the plane at
mgcos(teeta)-Un*N<F
where friction is involved then equation for the acceleration is
a=gcos+gsin.
where g is acceleration due to gravity