A crate is pulled across a horizontal, frictionless floor by a rope. At the same time, the crate pulls back on the rope, in accord with Newton's third law. Does the work done on the crate by the rope then equal zero?

Explanation:

If force F is applied on the crate , it will move with acceleration

a = F / m as no other force is acting on it .

This force is applied on the crate . work done by rope on crate  will be positive and equal to F x d where d is displacement .

The reaction force will apply on hand through rope. So work will also be done on hand by crate . This work will be negative as displacement in hand is opposite to direction of force on it.

a. is the answer because they are not shared

answer: 2×10^-2kg

explanation: density= mass per volume

vol=mass/density

converting to s.i units we have;

3÷1000kg = 0.003

1.5÷100m = 0.15

0.003/0.15 = 0.02kg