Question
Show that Newton’s first law of motion is contained in the second law.
Solution
First law of motion as a special case of second law.
Newton’s first law of motion can be deduced from second law.
That is,
when F = 0, v = u for whatever time t is taken because m ≠ 0.
This means that the object will continue moving with uniform velocity u throughout the time t. If u is zero then v will also be zero. That is the object will remain at rest. This is the same statement as Newton's law of motion.
Hence first law of motion is contained in the second law.
