What is the height of B from the ground?
You have to find the acceleration a of the system.
Then fall of potential energy = rise in kinetic energy.
An inclined slope at 30deg is smooth and A has mass 5kg whilst B has mass 20kg.
If the system is released from rest, use an energy balance equation to find the speed with which B hits the ground.
A is on the slope
B is hanging free.
where do i start?
Yeah, I think we can assume that B will not pull A over the edge.
So, to use the energy method, you must write down the conservation of energy equation. In order to do that, you have to define events. We'll call releasing the system event 1, with the corresponding subscripts. We'll call B hitting the ground event 2, with corresponding subscripts. Using for kinetic energy and for potential energy, we have the following equation:
Here the additional subscripts for and should be obvious.
Now, right off the bat, you know that because the system is released from rest. That gives you the equation
Furthermore, since A and B are connected by a rope that is presumably not stretchy, then A and B will be going at the same velocity when B hits the ground. That does not give us equality in the kinetic energy, though, since the masses are different. It is something to remember, though. That is, . Let's call the velocity . So the equation becomes
Now, in order to find the potential energy terms, you must define a coordinate system. What do you want to use?