I'm pretty sure that it's 815.
The statement that can be used to answer this question is:
"If the cylinder is brought higher then, its temperature when brought down becomes higher because a greater amount of potential energy is converted to thermal energy."
The potential energy is converted to thermal energy when the object is released the velocity becomes higher because of the acceleration due to gravity.
To solve this problem we will use the relationship given between the centripetal Force and the Force caused by the weight, with respect to the horizontal and vertical components of the total tension given.
The tension in the vertical plane will be equivalent to the centripetal force therefore

Here,
m = mass
v = Velocity
r = Radius
The tension in the horizontal plane will be subject to the action of the weight, therefore

Matching both expressions with respect to the tension we will have to


Then we have that,


Rearranging to find the velocity we have that

The value of the angle is 14.5°, the acceleration (g) is 9.8m/s^2 and the radius is



Replacing we have that


Therefore the speed of each seat is 4.492m/s
It would be a bike that doesn't use an electric circuit.
It is because gravity is pushing down on the ball