Christian wonders if a heavier cart will roll faster down-hill than a lighter one. He formulates a hypothesis and then decides to conduct an experiment. First, he finds a smooth ramp and a cart. He makes sure that the
wheels of his cart roll freely. He set the ramp against a chair so one side of the ramp was 0.5 m off the
ground. Next, he measures the distance the cart will travel down the ramp. He leaves about 10 cm at the top
of the ramp and draws a line to mark the release position of the car. He then measures the
distance the cart will travel down the ramp and has a stopwatch to time how long it will take to
reach the bottom of the ramp. He starts the experiment by measuring the time it takes the cart
to roll down the hill without any weight on it. For the next five trials he adds a 1 kg mass to the
cart each trial. The times of the trials were 1-27s, 2- 325, 3- 30s, 4-29s, 5-30s. When
comparing the data points, he decides to allow for a 5 second "fudge factor" since he may not
have released the cart at precisely the exact same spot each time. He finds that adding mass to
the cart does not affect the time it takes to roll down the ramp since all of his times were within
5 seconds of each other.