Observation is broken up into three parts. The first is the date. Then you have the activity and last you have a brief description of what is being observed.
When cool air sinks it forces warm air to rise is a example of convection.
Acceleration (a) is the change in velocity (Δv) over the change in time (Δt), represented by the equation a = Δv/Δt. This allows you to measure how fast velocity changes in meters per second squared (m/s^2). Acceleration is also a vector quantity, so it includes both magnitude and direction.
I found it in go ogle
