A 15-lb block B starts from rest and slides on the 25-lb wedge A, which is supported by a horizontal surface. Neglecting friction, determine (a) the velocity of B relative to A after it has slid 3 ft down the inclined surface of the wedge, (b) the corresponding velocity of A.

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