Physics URGENT!!!
posted by Anonymous .
Gayle runs at a speed of 9.00 m/s and dives on a sled, initially at rest on the top of a frictionless, snowcovered hill, that has a vertical drop of 20.0 m. After she has descended a vertical distance of 4.00 m, her brother, who is initially at rest, hops on her back, and they continue down the hill together. What is their speed at the bottom of the hill?
Gayle’s mass is 70.0 kg, the sled has a mass of 2.00 kg, and her brother has a mass of 50.0 kg.

Physics URGENT!!! 
bobpursley
energies gained=final energy
HerPE+HisPE+herinitalKE+hisInitialKE= finalcombinedKE + finalPE
+G*9.8*20+B*9.8*16 +1/2 G 9^2+ 0=1/2 (G+B)Vf^2+0
G is her mass, B is brothers mass, Vf is the finalspeed at bottom.
check my thinking. 
Physics URGENT!!! 
Anonymous
I don't think I am getting the right value, what are you getting?
Respond to this Question
Similar Questions

physics
a sled slides down a frictionless hill. if the sled starts from rest at the top, its speed is 7.5 m/s. a.) on a second run , the sled starts with a speed of 1.5 m/s at the top.. will it end with less than 9 m/s, 9 m/s, or more than … 
Physics
Gayle runs at a speed of 3.80 m/s and dives on a sled, initially at rest on the top of a frictionless snow covered hill. After she has descended a vertical distance of 5.00 m, her brother, who is initially at rest, hops on her back … 
physics
Josh starts his sled at the top of a 2.0 mhigh hill that has a constant slope of 25 degrees . After reaching the bottom, he slides across a horizontal patch of snow. The hill is frictionless, but the coefficient of kinetic friction … 
Physics URGENT!!!
Gayle runs at a speed of 9.00 m/s and dives on a sled, initially at rest on the top of a frictionless, snowcovered hill, that has a vertical drop of 20.0 m. After she has descended a vertical distance of 4.00 m, her brother, who is … 
Physics URGENT!!!
Gayle runs at a speed of 9.00 m/s and dives on a sled, initially at rest on the top of a frictionless, snowcovered hill, that has a vertical drop of 20.0 m. After she has descended a vertical distance of 4.00 m, her brother, who is … 
physics
Gayle runs at a speed of 8.00 m/s and dives on a sled, initially at rest on the top of a frictionless, snowcovered hill, that has a vertical drop of 14.0 m. After she has descended a vertical distance of 5.00 m, her brother, who is … 
physics
Gayle runs at a speed of 3.80 m/s and dives on a sled, initially at rest on the top of a frictionless snow covered hill. After she has descended a vertical distance of 5.00 m, her brother, who is initially at rest, hops on her back … 
physics
gayle runs at a speed of 4.00 m/s and dives on a sled, initially at rest on the top of a frictionless, snowcovered hill. after she has descended a vertical distance at a 5.00 m, her brother,who is initially at rest, hops on her back, … 
physics
A 30kg sled(with rider) slides without friction down a small, ice covered hill. On the first run the sled starts from rest and its speed at the bottom of the hill is 8.50m/s. On the second run the sled starts with a speed of 1.50m/s … 
physics
A sled slides without friction down a small, icecovered hill. If the sled starts from rest at the top of the hill, its speed at the bottom is 7.60 m/s. What is the height of the hill?