Physics help???????????????

Velocity is the derivative of position with respect to (wrt) time.

Acceleration is the derivative of velocity 'wrt' time....AND the second derivative of position wrt time.

Velocity is a vector...it has a direction and a magnitude. People OFTEN mistake/misuse velocity for speed.

e.g. Something goes 50 km/hr...that's a speed.

Something goes 50 km/hr east....that's a velocity.

Velocity and speed both are the change in position wrt time....as time changes the speed changes.

Acceleration is the change in velocity......NOT speed.......velocity wrt time. So the speed OR direction (or both) can change and give rise to an acceleration.

You could 'accelerate' in a car from rest at a stop light to say 60 mph in say 5 seconds or so and have an acceleration. You position doesn't change, but the magnitude of your velocity does.

You could stay at a constant 60 mph and then go around a curve....keeping your SPEED at 60 mph and still have an acceleration because your direction is changing. You're not going straight, you're going around the curve.

Does this help???

Velocity is derived from how long it takes you to cover a distance at a constant speed. If you travel 30 miles in one hour then you are going 30 miles every hour or 30 MPH.

Acceleration can be either positive or negative depending if you're speeding up or slowing down. Acceleration is what you feel when you put your foot on the gas pedal in a car. All it means is that you are changing speed.

The measurement for acceleration is metres per second per second (or m/s^2). Or how the velocity (speed) is changing every second.

If your speed changes at 9 metres/s^2 it means that every second your speed is increasing by 9 metres/second.

I really hope I've made that simple enough.