Derive from projectile motion equation

AI Thread Summary
To derive the equation R = v^2 sin(2θ)/g and show that R = V0^2/g, a solid understanding of projectile motion and trigonometry is essential. The discussion emphasizes the importance of sketching motion and creating velocity-time graphs for both horizontal and vertical components, as the area under the horizontal graph represents the range R. It notes that this problem may be challenging for beginners who have not yet learned key concepts like velocity, displacement, and Newton's laws. Participants suggest that acquiring skills in graphing and trigonometry is crucial for solving such problems. Online resources are recommended for those needing additional help with these foundational concepts.
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Homework Statement



Derive:
R=v^2sin2theta/g

Show that R=V0^2/g

Homework Equations





The Attempt at a Solution



This is my first time to take up physics so I have no idea at all on how to do this, to be honest.
 
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Start with a sketch of the motion, then draw the velocity-time graphs for the horizontal and vertical components.
The area under the horizontal graph is the range R.

This would be a very unusual problem for a first-time physics student.
Normally you would learn things like the definitions for velocity and displacement and drawing graphs and Newton's laws before you get to ballistics.
 
Thank you. There was no graph provided for this. Can this still be solved?
 
Also, I have no sufficient knowledge of trigonometry to be able to derive equations like this.
 
You have to make the graph yourself - it can also be done from the kinematic equations.
You do need trigonometry to divide the initial velocity into horizontal and vertical components.
You also need to know how to find the slope of a line and how to find the areas of a triangle and a rectangle.
If you do not have these skills, or the ability to sketch v-t graphs, then you need to acquire these skills before attempting problems like this one.

There are plenty of online sites that can help you.
 
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