233k views
5 votes
A roller coaster has a mass of 425 kg. It sits at the top of a hill with height 66

m. If it drops from this hill, how fast is it going when it reaches the bottom?
(Assume there is no air resistance or friction.)
A. 56.8 m/s
B. 91.3 m/s
C. 36.0 m/s
D. 12.5 m/s

User Suresh
by
8.4k points

2 Answers

4 votes

Answer:

36 m/s

Step-by-step explanation:

User WhiteleyJ
by
8.5k points
2 votes

Answer:

36 m/s

Step-by-step explanation:

Gravitational potential energy at top = kinetic energy at bottom

mgh = 1/2 mv²

v = √(2gh)

Given h = 66 m:

v = √(2 × 9.8 m/s² × 66 m)

v = 36.0 m/s

Rounded to two significant figures, the roller coaster reaches a speed of 36 m/s.

Step-by-step explanation:

User Eranga Heshan
by
7.9k points