Usain 9.58 https://www.youtube.com/watch?v=SyY7RgNLCUk
ball, ramp https://www.youtube.com/watch?v=zinszqvhaOk
usain graph https://www.youtube.com/watch?v=lGJWBtb-tcs
roller coaster https://www.youtube.com/watch?v=eIUkrNpcvAg