Ballistics ‘Simulation’ Assessment
| Student name | ||||
| Teacher name | Mr. Andrew / Mr. Paul S | |||
| Class | 11 Science in Practice | |||
| Date handed out | 3/5/2020 (wk 7) | Date due | 21/5/2020 (wk 9) | |
| Subject | Grade 11, QCE Science in Practice | Instrument no. | |
| Instrument | Forensic Science | ||
| Unit, Topic | Ballistics | ||
| Assessment Conditions | |||
| Time | Three weeks | Draft | 14/5/2020 (wk 8) |
| Other | ● Students will be granted three weeks to complete the task ● Students will be given an opportunity to submit ONE draft on the specified date to receive feedback in order to complete their assignment | ||
| Instructions | |||
| Students must investigate the motion of a bullet, (projectile), by altering the initial velocity and relating this to forensic ballistics. Students will carry out an investigation into Initial velocity using the Phet online simulation software as per the guidance in the method. They will record and analyse data, and draw conclusions from this. The conclusion must relate to the data AND the use of forensic ballistics in the field. | |||
| Criteria | Result | ||
| Knowing and Understanding | |||
| Analysing and Applying
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| Planning and Evaluating | |||
| Teacher Feedback:
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| Academic Honesty – Student Authentication | |||
| I acknowledge this is my own work and understand the consequences of failing to meet the expectations of the AIS Academic Honesty Policy. | |||
| Student signature | Date: | ||
Ballistics ‘Simulation’ Assessment
Use the following link to access the simulation – make sure you collect data with a student that has a device on which this simulation works.
https://phet.colorado.edu/en/simulation/projectile-motion
Hit the download button and follow the prompts to load the simulation
Introduction
- Write an introduction explaining the scientific concepts behind projectile motion, and give a specific example. Include your sources in the correct APA format in the reference list at the end.
| Introduction |
| A projectile is an object that has only one force acting upon it, the power of gravity when given initial velocity. The gravitational force influences its vertical motion, causing a vertical acceleration. Meanwhile, the horizontal movement results in the tendency of the object in motion to remain in motion at a constant velocity when air resistance is assumed. The initial velocity of the projectile can be altered by changing the angle of projection. There are three types of projectile. The first type is when a ball (or object) is being dropped from rest at a vertical motion. The second type is when a ball is being thrown upwards. Lastly, when a ball is being thrown upwards but with a horizontal angle. A projectile is any object that once dropped continues in motion by its own inertia and is influenced only by the downward force of gravity. This study investigates the relationship between the initial velocity and the distance traveled by the projectile. The change in the initial velocity is implied by changing the angle of projection. |
Aim and hypothesis
- Write an AIM and HYPOTHESIS for your experiment. Justify your hypothesis with a link back to the science you have learned about ballistics. Write these in the boxes below:
| AIM | To experiment with the motion of the bullet, which is projectile. By altering the initial velocity by varying the angle of projectionand relating it to forensic ballistics using the given website.
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| HYPOTHESIS | If the bullet is fired with a fixed amount of parameters but a different angle of projection, it will still slightly impact on a lot of variables. Some of the variables that will be changed are trajectory of the projectile, time of flight, height, and the distance. This will happen due to the fact that all these variables depend on the launch angle. |
Variables:
- What is your independent variable?
| Independent variable | The angle of projection. |
- What is your dependent variable?
| Dependent variable | The Range of the projectile (distance) |
- Use the following table to discuss your controlled variables. Ensure that you state WHY these need to be controlled and HOW they might be controlled in a real-life situation. State a minimum of 3.
| Variable | HOW controlled | WHY controlled |
| speed | This can also be done by altering the angle of launch or by changingthe initial force on the projectile. It can be controlled by making it faster or slower.
| It determines the Range. It is essential because it helps the bullet reach its aim in the necessary amount of time. |
| angle of launch | It can be controlled by changing the initial direction of the projectile. It can be reduced on increased depending on the position of the target. | The angle of launch determines the height, Range, and time of flight of an object in projectile motion. |
| initial height | it can be placed on a height for example a wall, hill, or on a roof. | It affects the time of flight hence determining the Range. The higher the initial height the longer the time of flight and therefore longer the Range. |
Method
- You will be altering either the initial speed (velocity), the angle of projection, or the mass of the projectile to see what effect this has on the Range. Choose at least 5 different values for the variable you are changing that will allow you to gather useful results. Put these in the table below:
| Chosen Variable | e.g Velocity, angle of projection, mass | |||||
| angle of projection | 25 | 30 | 45 | 56 | 67 | 79 |
- Design a results table in which to record your results. Insert this below:
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- Produce a line graph of your results. You may hand draw this OR use a computer program to generate it for you. Insert a picture/screenshot of your graph below:
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- Using the SEEL format, write a conclusion for your experiment. Remember to include the following:
- A statement relating Initial velocity to the Range of the projectile
- An example from your data AND graph to back up your statement
- A scientific explanation of WHY velocity has had this effect on the projectile’s Range.
- A link to forensic ballistics that suggests how this data could be used in a criminal investigation.
Write your conclusion in the box below:
| When the initial I velocity is higher, the Range of the projectile is farthest. The Range is a function of initial velocity, which depends on the angle of launch. The closer the angle is to 45 degrees, the more distant the Range of the projectile. The maximum Range for any initial velocity is at 45 degrees.It is because the value of Range is a function of the sine of twice the angle of launch. Sine is maximum at 90 0. Therefore it is achieved at 450. Thus the maximum Range is seen to occur at 45 degrees based on the graph of the data in question 8.This is the optimal angle where the force of gravity and the initial velocity balances to produce the maximum Range.By changing the angle of projection imply a change of the initial velocity. Initial velocity is a function of the sine of the angle. From this experiment, it is possible to determine the site at which a bullet was launched. It is notable that by changing the angle of projection, many parameters do change. By conducting ballasting and physical analysis, the position of the launcher can be found.
.https://passionatelycurioussci.weebly.com/blog/projectile-murder-mystery
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Evaluation:
- Discuss the limitations of a simulator as compared to real-life projectiles (e.g. the effect of air resistance and drag).
| The simulation neglects air resistance and the rotation of the earth. So, the projectile will never go as far as the simulation says, and it may not happen in a two-dimensional plane depending on which direction you are firing and how much time it spends in the air. There is always an optimal angle, but it may not be 45 degrees when there is air resistance.
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- Reference list:
| References | |
| 1 | https://vlab.amrita.edu/?sub=1&brch=74&sim=191&cnt=1 |
| 2 | https://passionatelycurioussci.weebly.com/blog/projectile-murder-mystery |
| 3 |