how do you do this physics problem?
Adolf and Ed are wearing harnesses and are hanging from the ceiling by means of ropes attached to them. They are face to face and push off against one another. Adolf has a mass of 126 kg, and Ed has a mass of 76 kg. Following the push, Adolf swings upward to a height of 0.65 m above his starting point. To what height above his starting point does Ed rise? (in meters)
Comments
sounds like a very realistic scenario....
use the information about the height to deduce the speed after being pushed; use that information in conjunction with the conservation of momentum to determine Ed's velocity and therefore his height rise
if Adolf rises to a height of 0.65m, then we know from energy conservation that his initial KE satisfies
initial KE = final PE
1/2 m v^2 = m g h or v = Sqrt[2 g h] = Sqrt[2 x9.8m/s/s x 0.65m] = 3.57m/s
now, we use conservation of momentun to find Ed's initial velocity:
initial momentum =0, so we have
0 = 126kg x 3.57m/s + 76kg V where V is Ed's velocity immediately after being pushed
solving for V: V = - 5.92m/s the minus sign indicating he moves in the opposite direction
now, the height he achieves also comes from
1/2 m v^2 = m g h or h = v^2/2g = (5.92m/s)^2/2 x 9.8m/s/s = 1.79m