Scenario+4

Christian's Cart Experiment

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 meters 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 his __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 are as follows:
 * = weight (kg) ||= time (seconds ) ||
 * 1 || 27 ||
 * 2 || 32 ||
 * 3 || 30 ||
 * 4 || 29 ||
 * 5 || 30 ||

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.

Complete each of the following:
 * 1) Identify Christian's hypothesis: A cart with more weight goes much faster
 * 2) Identify the independent variable: the weight
 * 3) Identify the dependent variable: does the cart increase in speed
 * 4) Identify the other variables Christian needs to consider/control during this experiment: are the wheels oiled, is the ramp at a constant angle and do the weights weigh exactly 1 KG. are the wheels/tires old and worn, are the axles bending under the weight, are they released at the same time or location, and do the carts follow the same path.
 * 5) Identify the control group in this experiment: the cart without the weight
 * 6) Identify the experimental group(s): 1-5 Kg. carts
 * 7) What conclusions might Christian draw from this data? depending on the weight the carts speed can increase and/or decrease
 * 8) What recommendations might you suggest for further study or for improvement? Release position, to have an accurate time and eliminate the "fudge factor"