When exiting off of an interstate, why does the car seem to go from 75mph to 50mph faster than 25mph to 0mph? The road composition, grade of the road, or the tires on the vehicle never changed, yet the car seems to maintain its velocity at the slower speeds.
In: Physics
In addition to what previous posts have said about air resistance, the brakes also play and important role. Brakes are fairly efficient at converting your kinetic energy into heat slowing you down quickly, while most cars use ICEs. That car can only accelerate at its quickest at peak power, which takes time for the engine to wind up.
Now, to directly answer why brakes help, is that they convert kinetic energy (movement) to heat via friction. Your brakes clamp down on of the rotor which spins with the wheels. Which means the faster the rotor spins the more heat generated therefore a faster slowdown.
I am not going to go into the physics via equations and stuff, but simply, when you are breaking the forward moment force stops. When you press the brakes the faster the speed of the wheels the faster you can remove the energy, so therefore you decelerate quicker because you can remove that energy quicker. Plus you also have tire resistance.
It’s been a while since I’ve done the actual math for this but if I remember correctly this should all be correct in a general sense
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