Einstein’s postulate that concerns the speed of light is that rulers and clocks cannot be used to measure the speed of light nothing can travel faster than the speed of light all uniformly moving observers measure the same speed of light the speed of light is defined as 3 e8 m/s

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