a small roller coaster starts at pt. A with a speed u on a curved path as shown in the fig. The friction between the roller coaster and the track

Question

is negligible and it always remains in the contact with the track . the speed of roller coaster at point D on the track will be :

[a] [ u² + gh ] ^1/2

[b] [u² + 2gh]^1/2

[c] [u² + 4gh]^1/2

[d] [u]

Answer 1

At point D, The energy is entirely kinetic. If the speed of the roller coaster at point D is v_d, then we have