Understanding of projectiles from physics

AI Thread Summary
The discussion focuses on understanding projectile motion in the context of Extension 2 mathematics for Australian high school students. The original poster seeks a crash course due to missed classes and an upcoming test, highlighting their existing knowledge of basic projectile concepts like horizontal and vertical components. Key advice includes mastering the relationships between time, position, velocity, and acceleration, particularly through different forms of expressing acceleration. Participants suggest using textbooks for examples and emphasize the importance of carefully reading questions to relate known variables to those required. Overall, the conversation aims to provide clarity and support for mastering projectile mechanics.
Mentallic
Homework Helper
Messages
3,802
Reaction score
95
I was unfortunate enough to have sports on the days of my mechanics classes so I've basically missed most if not all of the basics of this topic, and a test is coming up shortly.

What I need is a crash course on this topic. Extension 2 mathematics (Australian high school) on mechanics (projectiles in resistive mediums, pendulums etc.).

I already have a basic understanding of projectiles from physics and extension 1 maths, such as the horizontal and vertical components, displacement, velocity and acceleration etc.

I know a few formulas thus far such as:

w=\frac{d\theta}{dt}

v=rw

a=\frac{v^2}{r}

If you guys have any tips on the basic procedures required to solve each type of question, I would really appreciate it. I'll also be asking questions in the homework forum, without much attempt, because I'm seriously lost on all this.
 
Physics news on Phys.org


Wow I've seen you on the forums for so long and didn't even realize! I'm doing Ext2 Maths as well, I just had my trial this week!

Well if you have a couple of days, you can still cover it all in time. Start with resisted motion. The key is knowing the relations between the variables - time, position, velocity and acceleration.

You need to know the three forms to express acceleration:

a = \frac{dv}{dt} = v \frac{dv}{dx} = \frac{1}{2} \frac{dv}{dx}.
These allow to to describe the motion as functions of position as well as time. The key is to read the question carefully and express the information you have in the form that relates the variables know to the variables required.

If you want, get one of your textbooks and I'll help you though some examples and questions.
 


Oh wow you're doing ext2 maths? Your profile makes it seem like you're well into university already. (linear algebra, real and complex analysis?), I admire your ability to go ahead enough so that you can enjoy the topic. I attempted to learn linear algebra through the MIT lectures on youtube once... it was horrific by the 3rd lecture! There's no way one can understand everything just through lectures.

Thanks I'll keep those equations in mind, and I think you meant a=\frac{1}{2}\frac{d(v^2)}{dx} :smile:

I'll post links in here to the homework section, for ease.
 
The rope is tied into the person (the load of 200 pounds) and the rope goes up from the person to a fixed pulley and back down to his hands. He hauls the rope to suspend himself in the air. What is the mechanical advantage of the system? The person will indeed only have to lift half of his body weight (roughly 100 pounds) because he now lessened the load by that same amount. This APPEARS to be a 2:1 because he can hold himself with half the force, but my question is: is that mechanical...
Hello everyone, Consider the problem in which a car is told to travel at 30 km/h for L kilometers and then at 60 km/h for another L kilometers. Next, you are asked to determine the average speed. My question is: although we know that the average speed in this case is the harmonic mean of the two speeds, is it also possible to state that the average speed over this 2L-kilometer stretch can be obtained as a weighted average of the two speeds? Best regards, DaTario
Some physics textbook writer told me that Newton's first law applies only on bodies that feel no interactions at all. He said that if a body is on rest or moves in constant velocity, there is no external force acting on it. But I have heard another form of the law that says the net force acting on a body must be zero. This means there is interactions involved after all. So which one is correct?
Back
Top