I attached the missing picture.
We can figure this one out using the law of conservation of energy.
At point A the car would have potential energy and kinetic energy.
Then, while the car is traveling down the track it loses some of its initial energy due to friction:
So, we know that the car is approaching the point B with the following amount of energy:
The law of conservation of energy tells us that this energy must the same as the energy at point B.
The energy at point B is the sum of car's kinetic and potential energy:
As said before this energy must be the same as the energy of a car approaching the loop:
Now we solve the equation for
:
We can figure this one out using the law of conservation of energy.
At point A the car would have potential energy and kinetic energy.
Then, while the car is traveling down the track it loses some of its initial energy due to friction:
So, we know that the car is approaching the point B with the following amount of energy:
The law of conservation of energy tells us that this energy must the same as the energy at point B.
The energy at point B is the sum of car's kinetic and potential energy:
As said before this energy must be the same as the energy of a car approaching the loop:
Now we solve the equation for