Dr. Mosaddeq

Friction slows velocity, so to reach higher speeds friction would have to be reduced. The moving parts of a skateboard are likely where the wheels are screwed into the bearings. This is the most likely source of friction.

Plywood is a material. A safety hat is an object. Cement is a material. A pulley is a simple machine.

Surface area of a cirlce is simply its area, or pi(r)^2 Another way to express it is pi(diameter/2)^2 Remember that diameter is radius times two; radius is therefore diameter divided by two. Men: pi(24.3/2)^2 = 463.8 Women: pi(23.4/2)^2 = 430.1 Remember,...

With substitution: x + 8(-.025x) = 2 x + -.2x = 2 .8x = 2 x = 2/.8 = 2.5