Projectile Motion - lab report

Student name: karam Student name:

Student name: Student name:

Before start doing your report, read the following instructions:

1. Any value without unit will be considered not correct.
2. No more than 4 students for each lab report.

For Instructors use only

Knowledge __________________/2 points

[ K2 ]
• Student demonstrates relevant knowledge of the topic
• Student demonstrated the use of logic, math, and physical concepts to solve problems

Interpersonal Skills _________________/ 7 points

[SO 3]
• Student demonstrated skills in acquisition of data
• Student demonstrated analytical reasoning to interpret experimental data

Communication and IT Skills ________________/ 1

[SO 4]
• The Aim of the experiment was communicated effectively.
Values _________/ 2
[SO 6]
• Student was able to meet the set deadline.

TOTAL _____________________ /12 points

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 Communication
Part A [1 point]
Question 1: What is the main purpose of Projectile Motion experiment?

Interpersonal Skills
Part B (Results): [2 points]
Procedure 1: (when 𝜽 = 𝟎° ): Muzzle Velocity, Time of Flight & Range

Question 2: Do your work and record your data as the following:

Measure Range 𝑅 = ___0.65______ (m)

Initial Height 𝒚𝟎 = ____0.256____ (m)

gravity acceleration 𝑔 = 9.8 𝑚/𝑠 2

Time-of-Flight
𝑡1 + 𝑡1 + 𝑡1
𝑡1 𝑡2 𝑡𝑎𝑣𝑒 =
𝑡3 ____0.2215___𝑒𝑐 3
= _____0.2193__ 𝑠𝑒𝑐 = _0.2219_______𝑠𝑒𝑐 = __0.2209_____𝑠𝑒𝑐

Question 3: Now, calculate the following to complete procedure 1:

𝑅
Initial velocity (Experimentally) 𝑣0 𝑒𝑥𝑝 = = _____2.94________(m⁄𝑠)
𝑡𝑎𝑣𝑒

𝑔
Initial velocity (Theoretically) 𝑣0 𝑡ℎ𝑒𝑜 = 𝑅 √ = ______2.84____ (m⁄𝑠)
2𝒚𝟎

|𝑣0 𝑒𝑥𝑝 − 𝑣0 𝑡ℎ𝑒 |

% 𝒐𝒇 𝒆𝒓𝒓𝒐𝒓 𝒊𝒏 𝑖𝑛𝑖𝑡𝑖𝑎𝑙 𝑣𝑒𝑙𝑜𝑐𝑖𝑡𝑦 = × 100 = __3.52__________%
𝑣0 𝑡ℎ𝑒

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 Procedure 2: (when 𝜽 = 𝟑𝟎° ): recording the X, and Y positions:

Question 4: Do your work and record the data as the following:

Horizontal Position Vertical Position

(𝒙) cm (𝒙) meters (𝒚) cm (𝒚) meter

10 0.1 32 0.32
20 0.2 35 0.35
30 0.3 38 0.38
40 0.4 38 0.38
50 0.5 37 0.37
60 0.6 34 0.34
70 0.7 30 0.30
80 0.8 25 0.25
90 0.9 18 0.18
100 1.0 9 0.09

Interpersonal Skills
Part C (Analysis): [2.5 points]
Question 5: After doing your lab work, answer the following questions:

a) Plot a graph of x (in meter) Vs 𝑦 (in meter) on Excel and select Polynomial order 2
to find graph equation. Paste your graph with full information.

Chart Title
0.5

0.4

0.3

0.2

0.1 y = -0.7538x2 + 0.5758x + 0.2695

0
0 0.2 0.4 0.6 0.8 1 1.2

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 b) When you get graph equation, compare it with theoretical one to find 𝜃 𝑒𝑥𝑝 and
𝒈𝒆𝒙𝒑 (Show your work)

𝑔
The theoretical equation for a projectile is: 𝒚 = − 2 𝑣2 (cos 𝜃)2 𝒙𝟐 + tan 𝜃 𝒙 + 𝑦0
𝑜
Y=-0..7538x^2+0.5758x+0.256
Tan-1(0.5758)=29.93

𝜃 𝑒𝑥𝑝 =_____ 29.9333 _________

𝑔𝑒𝑥𝑝 =____3.0585_____ (𝑚/𝑠 2 )

𝑔
=2x2.94xcos(29.933^2)x0.65=3.0586
2 𝑣𝑜2 (cos 𝜃)2

c) Calculate the percentage of error in 𝜽 and 𝒈

𝜃 𝑒𝑥𝑝 − 𝜃 𝑡ℎ𝑒𝑜
𝑝𝑒𝑟𝑐𝑒𝑛𝑡𝑎𝑔𝑒 𝑜𝑓 𝑒𝑟𝑟𝑜𝑟 𝑖𝑛 𝜃 % = | | × 100
𝜃 𝑡ℎ𝑒𝑜

𝑇ℎ𝑒𝑜𝑟𝑖𝑡𝑖𝑐𝑎𝑙 𝜃 → 𝜃 𝑡ℎ𝑒𝑜 → 30°

𝐸𝑥𝑝𝑒𝑟𝑖𝑚𝑒𝑛𝑡𝑎𝑙 𝜃 → 𝜃 𝑒𝑥𝑝 → 𝑓𝑟𝑜𝑚 𝑡ℎ𝑒 𝑔𝑟𝑎𝑝ℎ 𝑒𝑞𝑢𝑎𝑡𝑖𝑜𝑛

29.9333-30/30x100=0.2223 =

𝑔 𝑒𝑥𝑝 − 𝑔 𝑡ℎ𝑒𝑜
𝑝𝑒𝑟𝑐𝑒𝑛𝑡𝑎𝑔𝑒 𝑜𝑓 𝑒𝑟𝑟𝑜𝑟 𝑖𝑛 𝑔 % = | | × 100
𝑔 𝑡ℎ𝑒𝑜

𝑇ℎ𝑒𝑜𝑟𝑖𝑡𝑖𝑐𝑎𝑙 𝑔 → 𝑔 𝑡ℎ𝑒𝑜 → 9.8 𝑚/𝑠 2

𝐸𝑥𝑝𝑒𝑟𝑖𝑚𝑒𝑛𝑡𝑎𝑙 𝑔 → 𝑔 𝑒𝑥𝑝 → 𝑓𝑟𝑜𝑚 𝑡ℎ𝑒 𝑔𝑟𝑎𝑝ℎ 𝑒𝑞𝑢𝑎𝑡𝑖𝑜𝑛

3.0585-9.8/9.8x100=67.8

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Part D (Simulation): [2.5 points]
Question 6: Open the simulator using the link below and click the link marked
“Lab”. Use this to answer the questions given.

https://phet.colorado.edu/sims/html/projectile-motion/latest/projectile-motion_en.html

a) What happens when the launch height is increased?

When the launch height is increased , the maximum height
Of projectile trajectory increases

b) Without changing anything, increase the mass and the diameter of the ball and
then launch it. What do you notice? Nothing change

c) Now add air resistance. What happens?

Will decrease the maximum height and horizontal range of

Projectile.

d) With Air resistance still added, decrease the mass of the ball. What do you notice?
Explain why this happens.

The projectile shorter horizontal range and maximum height

Because air resistance has greater impact on its motion due

To less mass

e) Add a screenshot of all your trials on the simulator below. Make sure your
snapshot clearly shows each of your attempts to answer the above questions.

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Knowledge
Question 7: Answer the following questions [2 point]

i. Projectile motion has two components, horizontal (x) and vertical (y). The horizontal
motion has:
A. Changing acceleration
B. Constant acceleration
C. Constant velocity
D. Both, constant velocity and constant acceleration

ii. From procedure 1, what effect does the mass of the ball have on the horizontal range?
Will a heavier ball of the same dimensions have a larger or smaller range?

A heavier ball of same dimension will have small horizontal range because heavy ball have greater gravitational
force making it more resistant to change in its horizontal motion as result will have short horizontal range
compare to lighter ball with same initial velocity

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