HOMEWORK 1. At time t = 0, a ball is thrown straight up at an initial velocity of 10 m/s, from Vo = 10 m /3 the top of a building 50 m tall. Neglect air friction h= 50 cm (a) When will the ball hit the ground? (b) How fast will it be going just before it hits the ground? (c) What was the average velocity of the ball over the entire time it was in the air? 2. Assume the distance from Stony Brook to NYC is 60 miles. Average speed = total distance elapsed time (a) If you travel from SB to NYC in 1.0 hour, what is your average speed? (b) if it takes 2.0 hours to return, what is your average speed for the return? (c) What is your average speed for the 3.0-hour round trip? 60 mi = 60 mph ) 60 mi 60 mi 2 hr = 30 mph 3 hr - = 20 mph 3. At time t = 0, a rock rolls horizontally off the edge of a 50 m high cliff. The rock's initial velocity is 10.0 m/s. Neglect air friction. (a) How much time will it take the rock to hit the (horizontal) ground below at point x? (b) What is the distance x? (c) What are the horizontal and vertical components of the rock's velocity vector just before it hits the ground? (d) What are the magnitude and direction of the velocity vector in part (c)