(b) If the ball misses the building on the way down, how much time does it take for the ball to strike the ground after it is thrown?
(c) What is the ball's velocity as it strikes the ground?
These problems may not be groundbreaking advances in modern physics, but they do represent very tangible everyday experiences: cars on roads, balls thrown in the air, hockey pucks on ice, and countless more examples can be modeled with these three relatively simple equations.
The first gives the change in velocity under a constant acceleration given a change in time, the second gives the change in position under a constant acceleration given a change in time, and the third gives the change in velocity under a constant acceleration given a change in distance.
We do not know why the velocity is constant; we do not know why the acceleration has a given value. Usually only two types of motions are considered in kinematics problems: Motion with variable acceleration is quite complicated.
Only in some special cases can we easily solve such problems, but usually we need to solve second order differential equations to get the answer in these problems.
Another difficult part in kinematic problems is related to the description of relative motion.
The equations of 1D Kinematics are very useful in many situations.
While they may seem minimal and straightforward at first glance, a surprising amount of subtlety belies these equations.
And the number of physical scenarios to which they can be applied is vast.