Consider a roller coaster that moves along the track shown in the figure below. Assume all friction is negligible and ignore the kinetic energy of the roller coaster's wheels. Assume the roller coaster starts with a speed of

Question

19 m/s at point A. Find the speed of the roller coaster when it reaches locations B and C.(Assume hA = 40 m and hB = 20 m.)
VB=____m/s
VC=____m/s

Answer 1

KE(A)+PE(A)=KE(B)
mv(A)²/2 +mgh(A)= mv(B)²/2
v(B)=sqrt[v(A)²+2gh(A)] =
=sqrt[19²+2•9.8•40) =33.84 m/s
KE(B)+PE(B)=KE(C)
mv(B)²/2 +mgh(B)= mv(C)²/2
v(C)=sqrt[v(B)²+2gh(B)] =
=sqrt[33.84²+2•9.8•20) =43.92 m/s