How do you find the vector sum of all the forces acting on an object?  We already looked at how to use a FBD to calculate the net applied force on an object, so now let's put it together with our knowledge about gravity (F_grav = mg) and friction (F_friction = μ f_normal) by using our equation: F_net = ma.

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Here's a friction experiment you can do to really see what's going on in the real world with friction:

Click here to go to next lesson on Air Resistance.

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