A 2 kg block is on a horizontal, frictionless plane. A string is attached to it and then goes over a pulley at the end of the plane. How much mass should you suspend on the other end of the string in order to obtain an acceleration of 3 m/s2?

An atom that has fewer electrons that protons is called a positive ion.

It should be d if not then c

The objects do not reach terminal velocity         there is not enough time from the time the object falls from when it hits the ground to achieve terminal velocity. an object must be placed higher to achieve terminal velocity in order to be in free fall.