Scientific Scenario #3
Monobl bra
Penny wonders if a heavier cart will roll faster down-hill than a lighter one. She forms a hypothesis and then
runs an experiment. She finds a smooth ramp and a cart and makes sure that the wheels of her cart roll freely
and sets the ramp against a chair so one side of the ramp is 0.5 m off the ground. She measures the distance
the cart will travel down the ramp and leaves 10 cm at the top of the ramp and draws a line to mark the release
position of the car. She 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. She 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 she adds a 1 kg mass to the cart each trial
(Time Trials: 1; 27s, 2; 32s, 3; 30s, 4; 29s, 5;30s). She decides to allow for a 5 second "error factor" since she
may not have released the cart at the exact same spot each time. She finds that adding mass to the cart does
not affect the time it takes to roll down the ramp since all of her times were within 5 seconds of each other.