In a manual car, why does going switching down gears make it easier/possible to to uphills?
In: Engineering
Forget the angles and the car and all of that.
Imagine trying to lift a piano. Naturally it would be very difficult. Now think about your grade school science class and specifically levers.
If you put a piano onto a teeter totter (lever) but have the part holding the teeter totter up (axis) closer to the piano you get what is called a mechanical advantage.
It becomes easier to move the heavy piano, but at a cost, you can’t move the piano as far because it is on the short side of the lever.
This is what the lower gears of the car are designed to do. They are made to make it easier to get the car moving from a stop, if you’ve ever tried to start moving in second gear you’ll understand it takes a significant amount more rpm to prevent stalling.
When you shift up, you are essentially moving the part holding the teeter totter up closer to the center, losing the mechanical advantage you had, and normally it is okay because your car is already moving.
When you start going uphill it is like shifting the part holding the axis of the teeter totter towards you, you are now at a mechanical *disadvantage* and start slowing down, and to compensate you must downshift, to get the mechanical advantage back, but like the teeter totter, the downside is you move slower.
Latest Answers