Physics help! Im having trouble understanding how the net force changes from the
ID: 1444562 • Letter: P
Question
Physics help!Im having trouble understanding how the net force changes from these two situations. I assumed that the net force would go down based on
Fnet=(ma+mb+mr)*a
So that would mean that the Fnet would get smaller as the the mass of the rope became smaller but the force applied to the block A and B would still be the same.
1) Is that a correct assumption? 2) If not how do the forces compare with different masses of rope? 3) if the rope became more smaller how would that affect the magnitude of the net force on the connecting rope and the magnitude of the forces exerted on rope by the objects?
Please help I. Blocks connected by a rope Two blocks, A and B, are tied together with a rope of mass M. Block B is being pushed with a constant horizontal force as shown at right. Assume that there is no friction between the blocks and the table and that the blocks have already been moving for a while at the instant shown. Rope has mass M
Explanation / Answer
1. No, it is not a correct assumption.
2. why, because
According to Newton's Third Law, the forces on these two masses must be equal (and in opposite directions). According to Newton's Second Law, F = m a, we find a = F / m. That means the acceleration of the twice-as-massive box will be one-half the acceleration of the other.
3. the pull of rope 2 on box B has greater magnitude than the pull of rope 1 on box B