What is uniform deceleration?

Answer 1

Answer 1

It means the change in speed is a constant, over the time interval in question. Another view is to plot speed versus time, you would get a straight line with a constant slope. For the geeks, it means the function representing distance versus time is a quadradic (power of 2), so that the second derivative (acceleration) is a constant. For example if the distance versus time is

D=3T**2

then the speed at any point in time is (the 1st derivative)

S=6T

and the acceleration is the 2nd derivative

A=6

which is no longer dependent on time (ie: it is a constant).

Answer 2

Deceleration is the negative form of acceleration, meaning when something is slowing down, i.e. that the velocity keeps decreasing as time keeps increasing until velocity reaches 0.

The uniform part concerns the rate of the slowing. Deceleration can have jerk, meaning that the change in velocity between two equidistant points in time is different. Uniform deceleration lacks jerk, meaning that all changes in velocity over time are constant. In lay men's terms, for example, when you stop a car by applying the breaks, the speed of the car might decrease from 35 to 30 miles per hour in one second and then decrease from 30 to 20 miles per hour in the next second. This shows jerk because in the first instance the deceleration was half of the second deceleration. If the example were changed so that in the second second, the speed dropped from 30 to 25 miles per hour, this would be uniform.

Therefore uniform deceleration is when something slows down at a consistent rate.