A compound machine is a combination of at least two simple machines. Simple machines can be a lever, a wedge, a while + axle, an incline plane, a pulley, and a screw.
There are many examples of compound machines. One of them is a showel that combines a wedge (the scoop part of shovel) and a lever (the handle to transfer the force to lift).
A much more complex compound machine is a bicycle, comprising simple machines ranging from wheels and axles, to screws, and levers (think of the pedals).
<span>the first one ( usually consists of fine sand, silt, and clay particles )
Hope im right!(: </span>
Answer:

Explanation:
When top block is just or about to slide on the lower block then we can say that the frictional force on it will be maximum static friction
So we will have






now for the Net force on two blocks to move together


