Newton's second law of motion suggests that the acceleration of an object is directly related to the force applied (more force, more acceleration), and inversely proportional to its mass (more mass, less acceleration).

The equation for this is:

This suggests that if the net force on an object is zero, the acceleration will be zero. Also, if the net force is not zero, there must be some acceleration.

Go to terminal velocity

We more commonly look at the above equation as


where the force on an object is equal to the acceleration of the object multiplied by its mass.

There are all kinds of consequences to this. Check out my notes:

Here are some questions about Newton's Second Law.

Combined with Newton's second law is PRESSURE.

Pressure is force applied per unit of area. (pounds per square inch, Newton's per square meter [Pascals])

Finding the pressure you put on the ground when you stand on one foot.

Find the number of square cm for your foot.

Divide by 10,000. This is how many square meters your foot takes up.

Find your weight in Newtons.

Divide this by your foot's area in square meters.

This is your pressure in Pascals.

And while we're at it, we can throw friction in here, treating it as one of the forces that needs to be added in a free-body diagram.

and some questions about friction.

Graphs from the coefficient of friction lab 2016

CXH 5 Review Questions