Question

Learning Goal To understand how the trajectory of an object depends on its initial velocity, and to understand how air resistance affects the trajectory. For this problem, use the PhET simulation Projectiie Motion. This simulation allows you to fire an object from a cannon, see its trajectory, and measure its height, range, and hang time (the amount of time in the air) 驵瘦. พี่ PHET Piojectile Motion Start the simulation by selecting the option labeled "Intro". Press the red Fire icon to launch an object. You can choose the object by clicking on one of the objects in the scroll-down menu at top right. To adjust the cannon barrel's angle, click and drag on it. You can also adjust the Initial Speed of the object using the toolbar at the bottom left. Clicking Air Resistance displays the drag coefficient for the given object and enables air resistance during motion. To measure the height, range, or hang time, drag the box that contains these quantities from the top of the screen to the various points of interest along the object's trajectory (use the crosshairs to locate the exact point of interest) Play around with the simulation. When you are done, click the Erase icon and set the object to a pumpkin prior to beginning Part A. For now leave Air Resistance unchecked

Answer 1

Part - A Air Resistance is neglected y_0 = 0 V_0 = 14m/s g = 9.8 m/s^2 Assume pumpin comes back to ground after �t� ses y(t) - position after �t� sec y(t) = 0 As pumpin comes back to ground and ground level y_0 = 0 (taken) given y(t) = y_0 + V_0 t - 1/2 gt^2 0 = 0 + V_0 t - 1/2 gt^2 V_0 t = 1/2 gt^2 t = 2V_0/g = 2 times 14/9.8 = 2.857 sec It takes 2.857 sec to hit the ground again