roller coaster prob.

[cowgiljl]

The mass of the coaster is 800 kg
The lift hill is 18 m highabd it goes up the lift hill at 2.50 m/s
The second hill is 5.5m high.

Wants to know the speed at the top of the second hill.
do i really care about the weight of the car?

This is what i have so far

PEtop1 +KEtop1 = KE bott
2*9.80*18 +2.5^2 = v^2 bott
V bott = 18.9 m/s

second formula was
Ke bott - Pe top1 = KE top 2
18.9^2 - 2*9.80*5.5 = V^2 top 2

Vtop 2 = 15.9 m/s and that is my final answer is that look right

thanks

[Hindi]

Yep...answer looks right to me.

[cowgiljl]

thanks hindi

[Hindi]

I believe the mass doesn't matter in this problem because the coaster is under constant acceleration for the whole run (gravity).