Read the motion

Position, velocity & acceleration, explained.

Velocity is the rate of change of position, and acceleration is the rate of change of velocity. A negative acceleration can slow an object traveling in the positive direction, then make it speed up in the negative direction.

The relationship to remember

x = v₀t + ½at² · v = v₀ + at

A worked example

With initial velocity 2 m/s and acceleration 1 m/s², after 4 s the position is 16 m and the velocity is 6 m/s.

Inside the default experiment

At t = 1.5 s: x = 2 × t + ½ × 1 × t² = 4.13 m.
v = 2 + 1 × 1.5 = 3.5 m/s.
End displacement at 6 s = 30 m.

When this model applies

One-dimensional motion starting at x = 0 with constant acceleration.

Make a prediction. Then test it.

Give the object positive velocity and negative acceleration. When does it turn around?

Try the interactive experiment ↗

A little question. A clearer picture.

Frequently asked questions

Wondering about the why? Start here.

What does the slope of a position graph mean?

The slope is velocity. A steeper upward slope means a larger positive velocity; a downward slope means negative velocity.

Is displacement the same as distance?

Displacement is final position minus initial position. Distance is the total length traveled, so reversing direction makes the two different.