The figure shows a famous roller coaster ride.You can ignore friction.If the roller coaster leaves point Q from rest,what is its speed at the top of the 25-m peak (point S)?

Question

Quizplus · Accepted Answer

Using the conservation of energy, the potential energy at Q is converted to kinetic energy at S, neglecting friction. The potential energy at Q is given by mgh, where m is the mass, g is the acceleration due to gravity and h is the height of Q. The potential energy at Q is equal to the kinetic energy at S, given by 1/2 mv^2, where v is the velocity at S. Setting the two equal and solving for v, we get:
mgh = 1/2 mv^2
2gh = v^2
v = sqrt(2gh)
h = 25 m
g = 9.8 m/s^2
v = sqrt(2*9.8*25) = 22 m/s

Therefore, the best choice is B) 22 m/s.

The Figure Shows a Famous Roller Coaster Ride