This read-only variable returns the speed as a value in pixels-per-second of the physics enabled instance. Should you need to change this value, you must do so by changing the x and y vectors using the variables phy_speed_x and phy_speed_y
Real (single precision floating point value, or undefined if the instance is not physics enabled)
if phy_speed > 10
phy_linear_damping += 0.01;
phy_linear_damping = 2;
The above code checks the speed of the physics enabled instance and then changes the linear damping based on the returned value.