I don't know if this is the right equation but in a question where it sakes the acceleration is 60%of the cars weight. Why does the mass cancel each other out so in the end you don't need to know the mass? Sorry I am typin this on my phone so I am sorry for the spelling errors Thanks Edit: some won understand what I mean. When they say the acceration is a certain percentage of the weight. Why do you multiply it but gravity. Essestially using the formula v2/r Can someone derive it for me. How does v2/r come about? How is there mass in the first place and why do you multiply it with the gravity constant of earth?