Aroller coaster starts from rest at the top ofan 18m hill.
the car travels to the bottom of the hill andcontinues up the next
hill that is 10.0m high.

v= 12.522 m/s

Explanation:

Supposing we have to find the velocity of the car

By conserving energy we can say that

Initial potential energy= Final potential energy + Final kinetic energy

So

also h{initial}=18 m

h_{final}=10 m

therefore,

0.5mv^2=mg(18-10)

So

v= 12.522 m/s

because if the tool that you are using is not balanced it there would be false mass.