Learn about air resistance and terminal velocity. A frictional force caused by air particles while an object travels through the air.
Air is made up of molecules and as a particle accelerates these particles are hit at an increasing rate. Air resistance builds up until Fair = -Fw. At this point an object has terminal velocity.
At Terminal Velocity:
- Fair = Fw (No net force)
- No acceleration
- Constant Velocity
Terminal velocity depends on the shape of an object(Aerodynamics). Terminal velocity is around 53 m/s or 122 mph for a human skydiver
Finding Acceleration with Air Resistance
Note: Unless a problem states there is air resistance assume none and g= 9.8 m/s2.
Until terminal velocity acceleration will be decreasing from 9.8 m/s2 until 0 m/s2
You can calculate the new acceleration by
- Finding the net force
- If you have weight but not mass calculate it using the equation: Fw = mg (air resistance does not affect an objects weight)
- Using the mass and the equation: Fnet = ma
Air Resistance Questions:
1. Draw a force diagram of an object with a weight of 300 N when 100 N of air resistance is encountered?
2. What is the acceleration of an object with a weight of 300 N when 100 N of air resistance is encountered?
3. Draw a force diagram of a 40 kg object that encounters 60 N of air resistance?
4. What is the acceleration of a 40 kg object that encounters 60 N of air resistance?