Physics unit 2- motion

Help us describe the motion of an object
Speed of an object is distance travelled each second
Gradient represents speed. Greater the gradient, greater the speed
If object stationary, line is horizontal
Constant speed =straight upwards slope
Speed(m/s)= distance travelled (m) divided by time taken (s)
Velocity is speed in a given direction
If changes direction, changes velocity. Even if same speed
If velocity changes, it accelerates.
Acceleration=final velocity minus initial velocity (m/s) divided by time taken for change (s)
If acceleration is negative, it's called deceleration
Acceleration is m/s squared

The gradient of a velocity-time graph represents acceleration
The steeper the gradient, the greater the acceleration
If line is horizontal, the acceleration is zero. Therefore the object is traveling at a steady speed
If the gradient of a line is negative, the object is decelerating

Calculating the area under the line between two times on a velocity-time graphs gives the distance travelled between those times.