Answer:
The velocity is 19.39 m/s
Solution:
As per the question:
Mass, m = 75 kg
Radius, R = 19.2 m
Now,
When the mass is at the top position in the loop, then the necessary centrifugal force is to keep the mass on the path is provided by the gravitational force acting downwards.


where
v = velocity
g = acceleration due to gravity

The minimum height h is 65m so that the car will not fall off the track at the top of the circular part of the loop.
<h3>What is mechanical energy?</h3>
Potential energy plus kinetic energy are combined to form mechanical energy. According to the principle of mechanical energy conservation, mechanical energy is constant in an isolated system when only conservative forces are acting on it. Potential energy increases when an object moves in the opposite direction of a conservative net force. Kinetic energy also changes as an object's speed, not velocity, changes. However, nonconservative forces, such as frictional forces, will always be present in real systems; however, if these forces are of minimal magnitude, mechanical energy changes little, making the idea of its conservation a reasonable approximation.
For completing the vertical circle the minimum speed at the bottom must be 
so conserving mechanical energy


⇒ h= 
h = 65m
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The cyclist who travels 20 kilometers per hour for 15 kilometers
Answer:
4.0 N
Explanation:
Sum the forces in the x direction:
∑F = ma
F − Fr = ma
Fr = F − ma
Fr = 5.00 N − (1.35 kg) (0.76 m/s²)
Fr = 4.0 N