Allow me to introduce myself. I am a high school junior who is very much interested in physics, mathematics, and learning in general. The reason why I am in love with physics can be traced back to my passion for cars. Now, going on age 17, I am exploring physics using this: http://ocw.mit.edu/courses/physics/8-01sc-physics-i-classical-mechanics-fall-2010/index.htm My problem has to do with solving the challenge questions on Units and Dimensional Analysis. Can someone help me?