Question

A roller coaster has a mass of 300 kg. It drops from rest at the top of a hill

that's 101 m tall. How fast is it going when it reaches the bottom?
Acceleration due to gravity is g = 9.8 m/s2.
A. 76.7 m/s
B. 44.5 m/s
C. 41.2 m/s
D. 21.8 m/s

Answer 1

To determine the velocity of the roller coaster as it moves down, we use the kinematic equation which is expressed as 2gy = vf^2 - v0^2 where g is the gravitational acceleration, y is the elevation of the roller coaster, vf and vo are the final and initial velocity. We calculate as follows:

2gy = vf^2 - v0^2

Since it starts at rest, v0 is zero.

2gy = vf^2

vf = √2gy

vf = √2(9.8)(101)

vf = 44.5 m/s ----> option B

Explanation: