Help please

If two students are running down the hall toward each other, trying to get to class, and they have the same mass and acceleration, what will happen when they collide? will their forces cancel out or will each one experience a reaction?

The precision of a voltmeter is ±0.005 v. the accepted value for a measurement is 9.016 v. which measurement is in the accepted range? 9.005 v 9.006 v 9.018 v 9.025 v

The focal length of a lens is determined by the curve of the lens and the material that the lens is made from. (5 points) is this true or false? ?