英文物理题,麻烦写出英文的回答,1. What is the formula for momentum,and is it a  vector?  2. Briefly state Newton’s Third Law   3. If a box is

英文物理题,麻烦写出英文的回答,
1. What is the formula for momentum,and is it a  vector?
  2. Briefly state Newton’s Third Law
  3. If a box is sliding to the right, what direction is the force of friction on the box?
  4. Name one  difference between  mass and weight.

1.p=m*v,where p is the momentum,m is the mass,and v is the velocity.The momentum is a vector.
2.Newton's Third Law:
For every action,there is an equal and opposite reaction.
3.To the left.
4.Mass is a measurement of the amount of matter something contains,while weight is the measurement of the pull of gravity on an object.
One difference:the mass of an object doesn't change when an object's location changes.The weight,however,can change with location.