Can anyone help to clear these up for me ? If you have a wedge on a horizontal frictionless surface, a block starts from rest and slides down the inclined surface of the wedge, is rough. During the motion of the block the center mass of the block and wedge --- - would it be moving horizontally with increasing speed ? and... Two bodies of unequal mass are at rest on a frictionless surface, and are acted on by equal forces for equal times. Just after these forces are removed, the body with greater mass will... - greater acceleration or speed, or smaller momentum? For this one i want to say greater acceleration but can anyone explain if this is right ?