Copy of PHYS110 Motion in Two-Dimensions Lab - STUDENT VERSION (2)

Siena College - General Physics 110 Motion in Two- Dimensions Lab NAME: Emily Brooks GROUP MEMBERS: Lisa, AG, Kamini, Sylvia Learning Goals 1. In Section I, you will investigate the horizontal and vertical components of a projectile’s velocity and devise an explanation related to whether or not each component of velocity is dependent on one another. 2. In Section II, you will design a new qualitative experiment to test the explanation that you devised in Section 1 related to whether or not each component of velocity is dependent on one another. 3. In Section III, you will quantify the launch speed of a projectile, and use this quantification to predict how far the projectile will travel when launched at a certain angle. Section I - In this part of the lab, you will investigate the horizontal and vertical components of a projectile’s velocity and devise an explanation related to whether or not each component of velocity is dependent on one another. Equipment: “Ball and Cart” video In this part of the lab, you will watch a video of a ball being launched when the cart upon which the ball resides is subject to either no horizontal push or different amounts of horizontal push. You will observe and record the patterns you notice for the motion of the ball and cart with respect to different frames of reference (for example: the cart’s motion relative to the table, etc.). You will then come up with an explanation for the direction of the launch that lets the ball land successfully back into the launcher. Scientific Ability Missing Inadequate Needs Improvement Adequate A6 Motion Diagram No representation is constructed. The motion diagram does not show the proper motion: either the lengths of the arrows (both velocity and velocity change) are incorrect or missing and/or the spacing of the dots are incorrect. The motion diagram has the correct spacing of the dots but is missing velocity arrows or velocity change arrows. The motion diagram contains no errors and it clearly describes the motion of the object. Dots, velocity arrows, and velocity change arrows are correct. B5 Is able to describe what is observed without trying to explain, both in words and by means of a picture of the experimental No description is mentioned. The description is incomplete. No labeled sketch is present. Or, observations are adjusted to fit expectations. The description is complete, but mixed up with explanations or patterns. The sketch is present, but it is difficult to understand. Clearly describes what happens in the experiments both verbally and with a sketch. Provides other representations when necessary 1

Siena College - General Physics 110 Motion in Two- Dimensions Lab setup. (tables and graphs). B9 Is able to devise an explanation for an observed pattern No attempt is made to explain the observed pattern. An explanation is vague, not testable, or contradicts the pattern. An explanation contradicts previous knowledge or the reasoning is flawed. A reasonable explanation is made. It is testable and it explains the observed pattern. A4 Is able to use representations to solve problems No attempt is made to solve the problem. The problem is solved correctly, but no representations other than math were used. The problem is solved correctly, but there are only two representations: math and words explaining the solution. The problem is solved correctly with at least three different representations (sketch, physics representation, and math OR sketch, words, and math, OR some other combination). Watch the video, “Ball and Cart”: https://www.islephysics.net/pt3/experiment.php?topicid=2&exptid=94 A. Observe the motion of the ball and the cart, and describe what you observe in simple words. The ball was launched from the cart moving in one direction. The ball launched up positively in the Y axis and negative in the x direction. The ball then reached it’s peak high and fell continuing in the negative x direction and negative y direction at the same but opposite angle of travel. B. Observe the motion of the cart with respect to the table. Draw a motion diagram representing the motion of the cart. In words, describe the motion of the cart relative to the table. The cart is moving in a linear line on the table. The cart will continue at a constant speed until an external force will be acted upon it. acceleration=0 --->--->--->--->--->--->---> ∆V =0 C. Observe the motion of the ball with respect to the cart. (It is helpful if you can step your video frame by frame.) Draw a motion diagram representing the motion of the ball with respect to the cart. In words, describe the motion of the ball relative to the cart. 2

Siena College - General Physics 110 Motion in Two- Dimensions Lab 1. Vf y 2 = Vo y 2 + 2 ay ∆ y 2. Vo y 2 = Vf y 2 − 2 ay ∆ y 3. Voy = √ 0 − 2 (− 9.8 ) X 0.95 = 4.32 m / s 4. height = 95 cm = 0.95 m Section II - In this part of the lab, you will design a new qualitative experiment to test the explanation that you devised in Section 1 related to whether or not each component of velocity is dependent on one another. Equipment: Marbles, projectile launcher, projectile balls, loading rod, larger balls, meter sticks, 2-meter sticks. Scientific Ability Missing Inadequate Needs Improvement Adequate C2 Is able to design a reliable experiment that tests the hypothesis The experiment does not test the hypothesis. The experiment tests the hypothesis. However, due to the nature of the design, it is very likely that the data will lead to an incorrect judgment. The experiment tests the hypothesis. However, due to the nature of the design, there is a moderate chance that the data will lead to an inconclusive judgment. The experiment tests the hypothesis and has a high likelihood of producing data that will lead to a conclusive judgment. C4 Is able to make a reasonable prediction based on a hypothesis No prediction is made. The experiment is not treated as a testing experiment. A prediction is made, but it is identical to the hypothesis OR a prediction is made based on a source unrelated to the hypothesis being tested, or is completely inconsistent with the hypothesis being tested, OR the prediction is unrelated to the context of the designed experiment. The prediction follows from the hypothesis, but is flawed because relevant experimental assumptions are not considered and/or the prediction is incomplete or somewhat inconsistent with the hypothesis and/or the prediction is somewhat inconsistent with the experiment. A prediction is made that follows from the hypothesis, is distinct from the hypothesis, accurately describes the expected outcome of the designed experiment, and incorporates relevant assumptions if needed. 4

Siena College - General Physics 110 Motion in Two- Dimensions Lab C7 Is able to decide whether the prediction and the outcome agree or disagree No mention of whether the prediction and outcome agree or disagree. A decision about the agreement or disagreement is made, but is not consistent with the outcome of the experiment. A reasonable decision about the agreement or disagreement is made, but experimental uncertainty is not taken into account. A reasonable decision about the agreement or disagreement is made and experimental uncertainty is taken into account. C8 Is able to make a reasonable judgment about the hypothesis No judgment is made about the hypothesis. A judgment is made, but is not consistent with the outcome of the experiment. A judgment is made, is consistent with the outcome of the experiment, but assumptions are not taken into account. A judgment is made, consistent with the experimental outcome, and assumptions are taken into account. A. Work with your group members to design a new qualitative experiment to test the explanation that you devised in Section 1 (part E). In section 1, recall that the experiments involved the ball and cart each having near identical horizontal velocities, but different vertical velocities. Now, think of an experiment where you could subject two objects to have near identical vertical velocities, but different horizontal velocities. 2 identical metal balls are released from an apparatus that is able to release the balls at the same height. One ball is dropped and the other ball is released in the horizontal direction. The time it take for the horizontally release and the vertically released balls will be analyzed B. Once you have designed the experiment, make a prediction of the outcome based on the explanation under test and write the prediction below. Make sure the prediction is based on the explanation from Section 1 (part E). Even though the balls are launched in different directions, the y-component, mass of the ball, and the force which each ball is pushed are the same for each ball, which means both balls should hit the ground at the same time. Our prediction is that velocity (Vx and Vy) are independent of each other. C. Conduct the experiment and record the outcome. The balls hit the ground at the same time, meaning that Vx and Vy are independent of eachother Pressure: 80psi Height: 1.96 meters Angle: 45˚ D. What is your judgement about the explanation you were testing? (After conducting this experiment, do you have reason to gain confidence in or reject the explanation that you were testing?) After conducting the experiment and analyzing the data, the prediction was confirmed. The ball with the higher horizontal velocity took the same amount of time to reach the bottom of its ramp as the other ball did. This result supports the 5

Siena College - General Physics 110 Motion in Two- Dimensions Lab down, press launch 4. record a video to determine the highest position of the ball in the air (to make the measuring easier. Procedure 2: 1. set angle of projectile device (45 degrees) 2. place the meter sticks on the floor for measuring point where ball will launch 3. pump bulb until the same value as 1st part of the experiment 4. put marble in the launcher and repeat previous step for launcher 5. determine the point of the floor where the ball lands Mathematical Prediction. Using the data you obtained from your experiment, calculate the initial speed of the projectile ball. Then, using the launch angle for your group, calculate how far the projectile ball should travel in the horizontal direction so you can place a target at your mathematically predicted location where the ball should land. Show every single step of your calculations in a neat and logical order. Make your prediction before running the experiment. Scientific Ability Missing Inadequate Needs Improvement Adequate A9 Mathematical No representation is constructed. Mathematical representation lacks the algebraic part (the student plugged the numbers right away), has the wrong concepts being applied, signs are incorrect, or progression is unclear. The first part should be applied when it is appropriate. No error is found in the reasoning; however, they may not have fully completed steps to solve the problem or one needs effort to comprehend the progression. No evaluation of the math in the problem is present. Mathematical representation contains no errors and it is easy to see progression of the first step to the last step in solving the equation. The solver evaluated the mathematical representation. 7

Siena College - General Physics 110 Motion in Two- Dimensions Lab pressure: 80 psi measurement from the 1st part (vertical distance): 1.96m measurement from the 1st part (horizontal distance): 3.51m outcome of experiment (horizontal): 3.4m Data Analysis. What may have contributed to any differences between the horizontal distance you obtained mathematically in comparison to the horizontal distance the projectile ball traveled when running your experiment? You should be able to identify several sources of experimental uncertainty. Scientific Ability Missing Inadequate Needs Improvement Adequate G 1 Is able to identify sources of experimental uncertainty No attempt is made to identify experimental uncertainties. An attempt is made to identify experimental uncertainties, but most are missing, described vaguely, or incorrect. Most experimental uncertainties are correctly identified. All experimental uncertainties are correctly identified. Air resistance could affect the trajectory of the ball when it is launched. The mathematical calculation may assume the ideal conditions without air resistance friction: between the projectile and the surface it travels on can affect its motion measurement errors: errors in measuring the initial velocity, launch angle, or distances traveled can contribute to discrepancies between the calculated and actual distances. These errors might arise from limitations in measurement tools projectile characteristics. variation in the shape, size and weight distribution of the projectile can affect its aerodynamics and trajectory. These characteristics were not accounted for. - distance measured may not be exact 8