Suppose a hiker, standing near the edge of a 416 meter tall cliff, throws a rock downward vertically off the cliff at a speed of 72 meters per second. Then the position of the rock t seconds after being thrown is: t) 1416 – 72t – 4.9t meters Determine the velocity and acceleration of the rock at the moment the rock impacts the ground. Round solutions to the nearest thousandth, if necessary. a. After how many seconds does the rock hit the ground below the cliff? seconds b. The rock's velocity at the point of impact is Select an answer v c. The rock's acceleration at the point of impact is Select an answer v Question Help: O Message instructor