Hello. I'm a physics student in high school, and I'm trying to design an experiment. I've encountered a small setback, though. 1. The problem statement, all variables and given/known data Investigating the relationship between the speed of a table tennis ball and the force of air resistance exerted upon it. 2. Relevant equations v^2=u^2+2as, v=u+at, f=ma, s=ut+1/2at^2 3. The attempt at a solution The purpose of this lab is to investigate the relationship between the speed of a table tennis ball and the force of air resistance exerted upon it. In order to perform this investigation, I will vary the speed of a table tennis ball under two circumstances, the first of which in a vacuum (the control group), where air resistance does not apply, and the second of which in a non-vacuum, where air resistance does apply. I will vary the speed of the table tennis ball by using a nichrome spring compressed to a certain length. I will calculate the force that will be generated using the formula F=kx. For both the control and the non-control group, for each trial performed, I will record the time taken for the table tennis ball to travel a fixed distance, s from the starting point thrice to obtain an average using a stopwatch. I expect to find a discrepancy in the time taken for the table tennis ball to travel to the fixed distance, s from the starting point between the control group and the non-control group due to air resistance in the non-control group. I expect the ball from the non-control group to take a longer time to reach s by virtue of the force of air resistance acting against the acceleration. From this discrepancy in time, I will calculate the force that is exerted upon the table tennis ball by air resistance. Sadly, I do not know how to. Will someone please teach me how to using the basic equations of motion please. Thanks. Please tell me what to substitute into a in the equation kx-ma= F of air resistance. Please also tell me: a) If an object travels a certain distance over a certain time period, I can obtain the speed by dividing the distance travelled by the time taken. Can I divide the speed by the same amount of time to obtain the acceleration of the object, assuming the initial speed is 0? b) if there is anything else that I should add to my experiment.