Suppose you throw a ball into the air. Do you think it takes longer to reach its maximum height or to fall back to earth from its maximum height? We will solve the problem in this project but, before getting started, think about that situation and make a guess based on your physical intuition.1. A ball with mass is projected vertically upward from the Earth's surface with a Positive initial velocity. We assume the forces acting on the ball are the force of gravity and a retarding force of air resistance with direction opposite to the direction of motion and with magnitude, where is a positive constant and is the velocity of the ball at time. In both the ascent and the descent, the total force acting on the ball is. [During ascent, is positive and the resistance acts downward; during descent, is negative and the resistance acts upward.] So, by Newton's Second Law, the equation of motion is Solve this differential equation to show that the velocity is2. Show that the height of the ball, until it hits the ground, is3. Let be the time that the ball takes to reach its maximum height. Show that Find this time for a ball with mass 1 kg and initial velocity 20 m # s. Assume the air resistance is of the speed.; 4. Let be the time at which the ball falls back to earth. For the particular ball in. Problem 3, the estimate by using a graph of the height function. Which is faster, going up or coming down?5. In general, it's not easy to find because it's impossible to solve the equation explicitly. We can, however, use an indirect method to determine whether ascent or descent is faster; We determine whether is positive or negative. Show that where. Then show that the function is increasing for. Use this result to decide whether is positive or negative. What can you conclude? Is ascent or descent faster?
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