In free fall near Earth's surface, the velocity changes by how many m/s, downward, during each second of flight? Enter the number only.
Hold a basketball in one hand and a golf ball in the other, both at shoulder height. Most people are sure the heavier ball will hit the floor first.
Let go of both at the same moment and each ball is in free fall. What you know about free fall decides which ball lands first.
That rate is the free-fall acceleration you've already seen: 9.8 m/s² downward. An object with ten times the mass gets no extra acceleration from it.
On Earth the test needs air resistance ignored or removed — free fall's own condition.
Two stones are dropped together from a bridge. One stone has twice the mass of the other. Air resistance is ignored. Compare their accelerations during the fall.
One more pair. A wrench and a small bolt are released together from the top of a ladder, with air resistance ignored. Neither one reaches the ground first: the wrench and the bolt land together. In free fall both accelerate at 9.8 m/s² downward, whatever their masses, so they stay level the whole way down.
Inside a sealed chamber with the air pumped out, a steel marble and a plastic bead are released from rest at the same height at the same moment. Which lands first?
A full paint can and an empty paint can slip off a shelf at the same moment. Air resistance is ignored. Compare their speeds while they fall.
A 2-kilogram melon and a 6-kilogram melon are pushed off a balcony railing at the same moment. Air resistance is ignored. Which melon hits the ground first?
A coin and a scrap of paper are sealed in a glass tube. With air inside, the coin lands first when the tube is flipped. The air is then pumped out and the tube is flipped again. What happens now?
A bowling ball and a tennis ball are dropped together from a high window. Air resistance is ignored. After both have fallen for 2 s, compare their speeds.