Projectile Motion Lab

Projectile Motion Lab Partner: Benny Huynh, Dennis Vo SPH4U Antonela Rusu Submitted by: Tommy Nguyen March 26 h , 2019 1

PURPOSE The purpose of this lab was to analyze the properties of downward projectile motion. This motion will show how the initial velocity and launch angle will impact the horizontal distance and the time. HYPOTHESIS The horizontal displacement and the time will not change since there is no change in initial velocity and launch angle. APPARATUS & METHOD PROCEDURE 2

textbook (m) 0.376 0.949 0.0899 0.345 1.09 1.06 1.52 0.222 CALCULATIONS & MANIPULATIONS Experimental Initial Velocity Theoretical Initial Velocity 4 ⃗ v i = √ ⃗ v x 2 + ⃗ v iy 2 ⃗ v i = √ ( 1.09 m / s ) 2 + ( − 1.06 m / s ) 2 ⃗ v i = 1.52 m / s θ = tan − 1 ( ⃗ v iy ⃗ v x ) θ = tan − 1 ( 1.06 m / s 1.09 m / s ) θ =[ E 44.2 ° S ] ∴ The experimentalinitial velocity was 1.52 m / s [ E 44.2 ° S ] . ⃗ v x ¿ θ ⃗ v iy ⃗ v i ⃗ d x = ⃗ v x ×t ⃗ v x = ⃗ d x t ⃗ v x = 0.376 m 0.345 s ⃗ v x = 1.09 m / s [ E ] ⃗ d y = ⃗ v iy t + 1 2 ⃗ a y t 2 ⃗ v iy = ⃗ d y − 1 2 ⃗ a y t 2 t v iy = − 0.949 m + 4.9 m / s 2 ( 0.345 s ) 2 0.345 s ⃗ v iy = 1.06 m / s [ S ] θ = sin − 1 ( ∆h l ) θ = sin − 1 ( 0.0899 m 0.222 m ) θ =[ E 23.9 ° S ] ¿ θ l ∆h

⃗ v i = √ 10 7 ⃗ g∆h ⃗ v i = √ 10 7 ( − 9.8 m / s 2 ) ( − 0.0899 m ) ⃗ v i = 1.12 m / s Percent Error for Initial Velocity %error = | experimental − theoretical | theoretical × 100% %error = | 1.52 m / s − 1.12 m / s | 1.12 m / s × 100% %error = 35.7 % Percent Error for Angle (θ) %error = | experimental − theoretical | theoretical × 100% %error = | 44.2 ° − 23.9 ° | 23.9 ° × 100% %error = 84.9% , 5

∴ The finalimpact velocity of the metalball was 4.57 m / s [ E 76.2 ° S ] EXPERIMENTAL UNCERTAINTIES 1. The amount of trial performed error. If it was increased, the average measurements would be more reliable. 2. The main source of error is likely to be the effect of air resistance, which is very difficult to account for theoretically at this level. When the projectile experienced more air resistance, it would not allow the projectile to complete its full motion. It would be the horizontal acceleration impact the horizontal velocity and horizontal displacement. 3. The accuracy of measurements, the smallest unit which allow 7 ⃗ v fy ⃗ v f

to measure is millimeter. This would only allow us to be so precise in calculations. Another uncertainty is the accuracy of stopwatch, it only allowed to measure to a hundredth of a second which could affect the precision of the experimental calculations. CONCLUSION After finishing this lab, I conclude that one of my hypothesis is correct while my other one had some problems. “The horizontal displacement and the time will not change since there is no change in initial velocity and launch angle.” This turned out to be true since the horizontal displacement and the time was about the same each trial. Performing this lab helped me understand downward projectile motion and how a downward initial vertical velocity changes regular projectile motion. It has also helped me understand the relationship between complimentary angles, their horizontal displacement and times. By increasing the amount of trials completed, it would help better understand the importance of launch angle and initial velocity. 8