Respuesta :
Answer:
Step-by-step explanation:
I think you mean 1/2 for 12. I will assume so
40 = (1/2) m v^2 Multiply both sides by 2
40*2 = (1/2)*2 *m * v^2 Combine the 2s cancel.
80 = m * v^2 Divide by v^2
80/v^2 = m * v^2/v^2 Cancel
80/v^2 = m
Since I don't have the drop down menus, you'll have do the matching.