Ward's World Activity Guides

Page 2 + ward ' s science 5100 West Henrietta Road • PO Box 92912 • Rochester, New York 14692-9012 • p: 800 962-2660 • wardsci.com Find materials for this activity at wardsci.com. Discover more free activities at wardsworld.wardsci.com Physics Projectile Project (continued) Standards: 9–12 a. Plan and conduct an investigation individually and collaboratively to produce data to serve as the basis for evidence, and in the design: decide on types, how much, and accuracy of data needed to produce reliable measurements and consider limitations on the precision of the data (e.g., number of trials, cost, risk, time), and refine the design accordingly. (HS-PS3-4) b. Analyze data to support the claim that Newton's second law of motion describes the mathematical relationship among the net force on a macroscopic object, its mass, and its acceleration. (HS-PS2-1) Conceptions a. A launched projectile has both x- and y- components of velocity and net force. b. The ax and ay and therefore ∑Fx and ∑Fy of a launched projectile remains constant for the duration of flight. c. The vx remains constant for the duration of flight. d. The initial and final vx share the same magnitude but have opposite directions (signs). e. A launched projectile reaches a maximum height when it's vy = 0 m/s. Misconceptions a. The range of a projectile relies solely upon the magnitude of its initial velocity. b. A vertically launched projectile accelerates at all points except at the maximum height when its velocity is zero. Time Requirements: Activity Time: (4) 90 minute lessons Pre-Requisite Learning: Students have prior learning related to velocity, acceleration, forces, position-time and velocity-time graphs in 1-dimension. Students have already worked with kinematics equations involving objects in freefall and fired directly vertically (objects with constant acceleration). Students are also familiar with trigonometric concepts as they relate to physics (this is done in the 2-dimensional motion unit for objects on slopes). Materials: • Baking soda • Vinegar • Film canisters (clear) • Plastic disposable pipettes Background Information, Activity Setup: The topic of study for these lessons is projectile motion, taught during the two-dimensional motion unit, which also includes circular motion concepts. The first lesson will consist of finding the maximum height of a projectile. The projectile, a film-canister, will be launched utilizing a ratio of baking soda & vinegar as a propellant. Students will test different ratios of baking soda & vinegar to find which combination allows the projectile to reach the highest maximum height. The second lesson will allow students to test which launch angle will produce the maximum range of their projectile. In theory, a projectile launched with an angle of 45 degrees provides the greatest horizontal distance of travel when launch and landing are on the same horizontal plane (this is an important logistical part of the investigation). Students will utilize the same ratio of baking soda & vinegar that provided the greatest height in their first investigation. Maximum height of the projectile will be found using video analysis. The frame rate (frames per second) will used to calculate the time for the projectile to reach its maximum height. Range will be measured using a metal measuring tape. Students will be grouped according to similar abilities. I also fashioned a cardboard launcher for part II of this lab. It had a protractor attached so that students could adjust for different angles fairly quickly. Instructors can have students devise their own angled launch methods or create a class set for them.

• Cover