Question :A small roller coaster starts at point 𝐴 with a speed 𝑢 on a curved track as shown in figure The friction between the roller coaster and the track is negligible and it always remains in contact with the track. The speed of the roller coaster at point 𝐷 on the track will be
(A) \left( u^{2}+gh\right) ^{\dfrac{1}{2}}
(B) \left( u^{2}+2gh\right) ^{\dfrac{1}{2}}
(C) \left( u^{2}+4gh\right) ^{\dfrac{1}{2}}
(D) u
Answer : option (D)
Solution :
