Question

Why do we need inertia?

@shifuyanli

Answer 1

Well, two examples of when we use or have inertia can be...
A. You are in a car riding at a high speed. Then out of no where, you see a red light. You slam on the breaks. When this happens you jolt forward. You jolting forward is inertia. Inertia is the force that made you jolt forward.
B. You are on your bike riding at a high speed. You make a left turn and see a car right in front of you. You (once again) slam on your breaks. This causes the bike to turn a bit and make a skid mark on the street. The friction between your bike tire and the street was caused by Inertia.
So basically, we use alot of Inertia when we are riding on something, and then hit our brakes. That's why we wear a seat-belt in a car, and a helmet on a bike. Because sometimes, Inertia can pull us forward and we will fly-out of the window, or if on a bike, crack your head open. Remember. Basically, the definition of Inertia is,
An object in motion wants to stay in motion, while an object at rest wants to stay at rest.

Answer 2

Thank you! I know that we need/use inertia for sports, but I didn't know we used it for driving, riding a bike etc... So thanks :)

Answer 3

yw :P