A student wants to know if the effect of gravity is the same on all objects. She follows these steps: 1 :Drop a 5-gram ball, a 10-gram ball and a 12 gram ball from a height of 10 meters.
2 :Record how long it takes for each object to hit the ground
3:?

Which step should be next?

Choose new balls

Measure the mass of the balls again

Drop the balls from a different height

Perform a second trial