Background Paragraph: Gravity is a force that pulls objects down toward the ground. When objects fall to the ground, gravity causes them to accelerate. Acceleration is a change in velocity, and velocity, in turn, is a measure of the speed and direction of motion. Gravity causes an object to fall toward the ground at a faster and faster velocity the longer the object falls. In fact, its velocity increases by 9.8 m/s 2 , so by 1 second after an object starts falling, its velocity is 9.8 m/s. By 2 seconds after it starts falling, its velocity is 19.6 m/s (9.8 m/s + 9.8 m/s), and so on. The acceleration of a falling object due to gravity is illustrated in the Figure below . For a more detailed explanation of acceleration due to gravity, watch this video:. 
Story: Adam is doing an experiment for his science fair. He takes a bowling ball and drops it onto a piece of foam, then records how big of a dent it makes. When he dropped the ball at 3 feet it left a very shallow dent. When he dropped the ball from 7 feet it broke strait through the foam and shattered it. 
Question: Given two identical cellphones, A and B, which is more likely to break, Cellphone A dropped at 3 feet or Cellphone B dropped at 6 feet?
Cellphone B.