A car is travelling at a speed of 90km/h. On seeing baby 20m ahead on the road, the driver jamed on the breakes and it came to redt at a distance of 15m. What is ots ratardation and how long does it take to come rest

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