# Kinematic equation

1. Dec 3, 2004

### jlorino

in a kinematic equation when you throw a ball up and it reaches its highest point its velocity becomes zero how long is it zero

2. Dec 3, 2004

### Tide

In the idealized description of the trajectory, its speed is zero instantaneously, i.e. the duration of zero speed is itself zero! Ultimately, of course, your measurements have limited resolution and air turbulence will contribute to uncertainty.

3. Dec 3, 2004

### franznietzsche

or more simply, the velocity is always changing, it is never constant, so the velocity never stays at any value. It passes through the value zero at a certain time,but it does not stay that value.

4. Dec 3, 2004

### jlorino

in my thinking that there are infinite numbers so you could measure time presicely infinite so something being instantanous would not be possible

5. Dec 3, 2004

### HallsofIvy

"measure time precisely infinite" makes no sense. In any case, I would think "there are infinite numbers" would mean that you CAN have something "instantaneous"- that's basically what non-standard analysis is about.