I'm doing a lab were we used photogates to calculate the time before and after the collision. I have an initial Photogate Time and a Final Photogate Time.. Working in excel I need to caculate the velocity final and initial using those times. I also need to find KEi KEf Pi and Pf. I've dervived how to find KEi (1/2(830) vi^2, KEf (1/2(1160)Vf^2), Pi (830*Vi), Pf (1160* Vf) for when Ma >> Mb I don't know why I just can't seem to figure how to calculate Vi and Vf using the photogate values. please help!