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14 votes
14 votes
As a roller coaster car crosses the top of a 48.01-m-diameter loop-the-loop, its apparent weight is the same as its true weight. What is the car's speed at the top?

User Pinglock
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3.2k points

2 Answers

11 votes
11 votes

Answer:

The speed is 15.34 m/s.

Step-by-step explanation:

Diameter, d = 48.01 m

Radius, R = 24.005 m

Let the speed is v and the mass is m.

Here, the weight of the car is balanced by the centripetal force.

According to the question


m g = (mv^2)/(R)\\\\v =√(24.005*9.8)\\\\v = 15.34 m/s

User Goldengirl
by
3.1k points
29 votes
29 votes

Answer:

The speed of the car, v = 21.69 m/s

Step-by-step explanation:

The diameter is = 48.01 m

Therefore, the radius of the loop R = 24.005 m

Weight at the top is n = mv^2/R - mg

Since the apparent weight is equal to the real weight.

So, mv^2/R - mg = mg

v = √(2Rg)

v = √[2(24.005 m)(9.8 m/s^2)]

The speed of the car, v = 21.69 m/s

User Alexey Kulikov
by
2.6k points