# Shouldn't deltaTime be defined as the 1 over the time interval between two frames?

I tried to consider it like this:

Suppose an object moves 3 meters between one frame and the next, and it takes 2 secs. If you multiply them directly like in the reference example, it gives us 3 meters/ frame * 2 secs /frame = 6 meters * sec / frame^2, whereas what actually occurs is it moves 3 meters in 2 seconds, that is 3/2 = 1.5 meters/second.

Also, why is it that in the example, 10 meters/frame retained its magnitude to 10 meters/second?

The script example is correct. `Time.deltaTime` is definitely a time, and is the time between this frame and the last frame. So, if you were rendering at 100fps, then `deltaTime` would be 0.01s. In the example the object is moving at 10m/s. It’s not accelerating, just has constant velocity. So, if you multiply `deltaTime` (a time) by a velocity (in metres per second) you get a distance in metres, which is how far the object moved in that time.

I didn’t fully understand your math, but possibly you’re making things more complicated than it needs to be.

distance, d = 3 meters
time, t = 2 seconds
deltaTime, x ( the time need for 1 frame to show )

Your first equation is wrong to begin with. Let’s do this calculation to see why(based on your first equation)

``````Velocity = 3 meters/ frame * 2 secs /frame

Let frame be 1
// I don't care what frame is right now, deltaTime,
// or number of frame per second, it doesn't matter

Then,

Velocity = 3 meters/ 1 * 2 secs /1
= 6 meter * 1 second
``````

What does `6 meter * 1 second` means? It is meaningless, it is definitely not `velocity` ( meter per second ), nor can it mean anything else.

## Further Inspection

When you move 3 meters in 2 seconds, your velocity, `V` is

``````V = d/t
V = 3 / 2
= 1.5 meter per seconds
``````

When you said `d/x` (3/frame), this is not related to the original question at all, you are saying that

``````distance travelled per delta time
``````

So, you are now talking about the speed required to travel 3 meter per 1 frame

``````If we are running 25 fps, deltaTime = 1sec/25frame = 0.04 seconds
d/X = 3 meter / 0.04 seconds
= 75 meter per seconds
``````

Your second part is 2 sec/frame, which is `t/x`, which translate to

``````2 seconds divides by time required to finish 1 frame
``````

which will become, `total number of frame in 2 seconds`

``````If we are running 25 fps, deltaTime = 1sec/25frame = 0.04 seconds
t/X = 2 seconds / 0.04 seconds
= 50 frames
``````