If four similar cars carrying different number of people, were to travel down the same slope, which car will travel faster down the slope?
This is wrong logic. All the cars will go down with same speed. The acceleration is same for all objects. Only when there is significant air resistance will the speeds be different. E.g., bullet vs. a feather. Look for Galileo's experiment. In this question, the air resistance will not be any different across the 4 choices.
ASHMI , you are confusing me and others also I think . Firstly you said - please explain then you said the answer is A then in the experiment in first line you said the answer is D but in the last line you wrote the answer is A !!!!! C an you explain what is the correct answer in your eyes A or D ?
Answer is D as gravitational force acts quicker on the heavier object.You can try an experiment related to this answer.Throw a plastic bottle cap and metal bottle cap OR a sheet of paper and a glue bottle OR any two such things so that one is heavy and the other one is light. Then throw them from the same height and at the same time. Then you'll get the answer i.e. the heavier thing fell before the lighter thing. I tried this experiment after giving my first opinion (OPTION A-you can see it) and it gave me good results.
OK YOU ARE TELLING THAT AIR BUT E.G., STEEL BALL VS SPONGE BALL IN SLOPE SEE BELLIONS EXPERIMENTS, HE WILL PROVE THAT ON 76TH EXPERIMENT