11) In 2002, professional skateboarder Bob Burnquist became the first to successfully navigate a 360° full pipe turn. Determine the minimum speed which would be required at the top of the circular loop to make it through the 1.8-m

radius pipe.

If a rock is thrown upward on the planet mars with a velocity of 12 m/s, its height (in meters) after t seconds is given by h = 12t − 1.86t2. (a) find the velocity of the rock after two seconds. m/s (b) find the velocity of the rock when t = a. 12−3.72a m/s (c) when will the rock hit the surface? (round your answer to one decimal place.) t = s (d) with what velocity will the rock hit the surface? m/s

Ais on of a in a of r at v. by ofof b by a of ? 13.by a of .by a of .by a of .by a of . a) b) c) d)

What would occur if the index of refraction of a material was less than n=1? the speed of light would increase to a speed larger than the maximum speed of light in a vacuum. the light wave would not bend at all though the material. the light wave would not be able to refract and would instead reflect off of the material. the speed of light would reduce to values close to 0 m/s.