SCIENCE 101

Name: Tutor victor Date: 4/25/2023 Student Exploration: Golf Range Directions: Follow the instructions to go through the simulation. Respond to the questions and prompts in the orange boxes. Vocabulary: acceleration, air resistance, gravity, hang time, launch angle, projectile motion, trajectory, vector, velocity Prior Knowledge Questions (Do these BEFORE using the Gizmo.) 1. You are in a contest with your friends to see who can drive a golf ball the farthest. Should you hit a “line drive” (low to the ground) or a shot with a very high angle? Explain. 2. Golf drives travel much farther than Major League home runs. Why might this be? Gizmo Warm-up Have you ever hit a hole-in-one? You will have a chance to do that in the Golf Range Gizmo, where you will see how a variety of factors affect the path of a golf ball. The movement of objects such as a ball through space is called projectile motion. 1. Press Play ( ). Did the ball go too far, the right distance, or not far enough? 2. Click Reset ( ). Move the vinitial and θ sliders to adjust the velocity and launch angle until you get a hole-in-one. (With the Gizmo sound on ( ) you will hear “Hole in one!”) 3. Can you get holes-in-one using other combinations of vinitial and θ? If so, give an example. Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved Activity A: Maximum distance Get the Gizmo ready: ● Click Reset and check that Atmosphere: Air is selected. ● Set vinitial to 75 m/s and θ to 45.0 degrees. Question: What launch angle will produce the longest drive? 1. Form hypothesis: 2. Experiment: Turn on the Show grid checkbox. With the velocity set to 75 m/s, experiment with a variety of launch angles until you find the one that yields the longest driving distance. A. What launch angle produced the longest drive? 41 degrees B. How far did the ball travel? 355m 3. Observe: Click Reset and turn on Show paths. Click Clear paths. Take a swing with the optimum launch angle. The curved path the ball takes through the air is its trajectory. The curve is slightly steeper on the right than on the left as a result of air resistance. 4. Experiment: Click Reset, then select Atmosphere: None. As before, use trial and error until you find the launch angle that produces the longest drive. A. What launch angle produced the longest drive? 44 degrees B. How far did the ball travel? 555 m C. Why do you think the ball traveled farther in this situation? It traveled that far because there was no air resistance 5. Extend your thinking: The Moon has much less gravity than Earth and has an extremely thin atmosphere. How would these factors affect the trajectory of a golf ball on the Moon? Activity B: Get the Gizmo ready: Physics of projectile motion ● Click Clear paths and select Atmosphere: None. ● Turn off Show grid and Show paths. ● You will need a scientific calculator for this activity. Introduction: Velocity is an example of a vector quantity because it describes the speed and direction of an object. The velocity of an object through space can be shown by two components: a horizontal component (vx) and a vertical component (vy). Question: How does the velocity of an object change as it flies through space? 1. Observe Click Reset. Turn on Show velocity vector and Show velocity components. Set vinitial to 50 m/s and set θ to 45.0 degrees. Click Play. Focus on the blue and red arrows that represent the vertical and horizontal components of the golf ball’s velocity. A. As the ball flies through the air, what do you notice about the blue (vertical) arrow? The blue barrow was not present at the top of the parabola and gravity was only affect on the way down B. As the ball flies through the air, what do you notice about the red (horizontal) arrow? the red arrow does not change at all because it is in a horizontal motion C. Try other velocities and launch angles. Do these results hold up? Yes they do 2. Calculate: You can use trigonometry to find the initial horizontal and vertical components of the ball’s velocity. Take out your calculator now. Click Reset, and turn off Show velocity vector and Show velocity components. Set vinitial to 50.0 m/s and θ to 60.0 degrees. A. To calculate vx, multiply vinitial by the cosine of the angle: vx = vinitial • cos(θ): 25 m/s B. To calculate vy, multiply vinitial by the sine of the angle: vy = vinitial • sin(θ): 43.30 m/s C. Turn on Show velocity components. Were you correct? yes 3. Analyze: An object flying through the air is said to be in free fall. As you observed, the horizontal component of velocity (vx) does not change as the object moves, but the vertical component (vy) decreases over time. (Note: Air resistance is not included in this model.) A. What force causes vy to change as the golf ball travels? The mass of the golf ball B. Why doesn’t vx change as the object travels? (Hint: Are there any horizontal forces acting on the ball?) No forces are acting on it 4. Set up Gizmo: Acceleration is a change in velocity. As the ball moves through its trajectory, it undergoes a downward acceleration due to the force of gravity. To calculate the acceleration of a falling object, divide the velocity change by the time interval. a = (vcurrent – vinitial) / t Set vinitial to 75.0 m/s and θ to 60.0 degrees. Record the initial vertical velocity of the golf ball in the first row of the table below. Include all units. Time (s) vy (m/s) 0.00 s 75 m/s 13.25 -64.95 m/s