Question

Is the fourth equation of motion dimensionally correct? Please explain why or why not.

Answer 1

First, an equation could work with different units if there is an implied conversion factor of 1. Like if your talking about photons, and had Planck distance on one side, and Planck time on the other; the conversion requires c, the speed of light, which is 1 in Planck units.

That being said,  s= u + a/2*(2n-1) is NOT correct. It implies that if you do not accelerate, you do not move. (if a=0, then s=u)If I travel at a starting velocity of 3m/s, maintain a constant acceleration of 0 for 5,000 years, I've traveled significantly farther than 3 m.

The correct from should be something like s=un+12an2