Formula help Can someone help me find the right formula for these two question....i dont want the answer just help with the formula

Paco rode his skateboard up a ramp for a distance of 3.8 meters. If the ideal mechanical advantage of the ramp is 2, how far above the ground was Paco?

I think it is 3.8 x 2 = ? but i am unsure

Lucas has been challenged to increase the efficiency of a device he is redesigning. His goal is 90 percent efficiency. The work input of the device is fixed at 10 joules, so Lucas is trying to improve work out

Question

Formula help            Can someone help me find the right formula for these two question....i dont want the answer just help with the formula                                             

Paco rode his skateboard up a ramp for a distance of 3.8 meters. If the ideal mechanical advantage of the ramp is 2, how far above the ground was Paco?

I think it is 3.8 x 2 = ? but i am unsure

Lucas has been challenged to increase the efficiency of a device he is redesigning. His goal is 90 percent efficiency. The work input of the device is fixed at 10 joules, so Lucas is trying to improve work out

anonymous · Answer

second one i think is 90 x 10 = Output

phi · Answer

See http://interactagram.com/physics/dynamics/MechanicalAdvantage/ramp/ for a picture of what mechanical advantage of a ramp means.

phi · Answer

the mechanical advantage of a ramp is   "distance up" divided by the length of the ramp