An object, initially at rest, is pushed across a level, frictionless table by a
ID: 2261736 • Letter: A
Question
An object, initially at rest, is pushed across a level, frictionless table by a horizontal force FappObj for a time interval Dt. Sometime after the force has ceased its pushing, the object reaches the edge of the table and falls freely toward the floor below. After it has fallen a vertical distance d (but before it reaches the floor, the object explodes into two pieces, A (mass = mA) and B (mass = mB). Piece A An object, initially at rest, is pushed across a level, frictionless table by a horizontal force FappObj for a time interval Dt. Sometime after the force has ceased its pushing, the object reaches the edge of the table and falls freely toward the floor below. After it has fallen a vertical distance d (but before it reaches the floor, the object explodes into two pieces, A (mass = mA) and B (mass = mB). Piece A An object, initially at rest, is pushed across a level, frictionless table by a horizontal force FappObj for a time interval Dt. Sometime after the force has ceased its pushing, the object reaches the edge of the table and falls freely toward the floor below. After it has fallen a vertical distance d (but before it reaches the floor, the object explodes into two pieces, A (mass = mA) and B (mass = mB). Piece A An object, initially at rest, is pushed across a level, frictionless table by a horizontal force FappObj for a time interval Dt. Sometime after the force has ceased its pushing, the object reaches the edge of the table and falls freely toward the floor below. After it has fallen a vertical distance d (but before it reaches the floor, the object explodes into two pieces, A (mass = mA) and B (mass = mB). Piece AExplanation / Answer
acceleration for Dt time = FappObj / (mA + mB)
velocity(Vx) after Dt time = FappObj*Dt / (mA + mB)
after fallen d distance
velocity in y direction due to gravity = - sqrt(2*g*d)
velocity in x direction = FappObj*Dt / (mA + mB)
after explosion
velocity of A in x direction = 0
velocity of B in x direction = [ (mA + mB)*FappObj*Dt / (mA + mB) ] / mB = FappObj*Dt / mB
after colliding with floor
velocity of B in x direction = FappObj*Dt / mB
velocity in y direction = 0
before coliding with object C
velocity of B in x direction = FappObj*Dt / mB since, floor is friction-less
velocity in y direction = 0
after colliding with object C
Velocity of combined mass B&C in x direction = [ mB*FappObj*Dt / mB ] / (mB + mC) by momentum conservation
= (FappObj*Dt) / (mB + mC)
velocity in y diection = 0