How Do You Solve These Physics Problems Using Component Methods?

[thugg]

i can't remember how to do this at all, but can someone just post a simple step by step solution for this? thanks

http://img275.imageshack.us/img275/2392/ss2mx.jpg




also this one I am having trouble with



http://img374.imageshack.us/img374/1146/dfsd4mu.jpg

 

[Corneo]

Use Newton's second law, F = ma and isolate the force components.

 

[teclo]

why don't you start by drawing the force vectors and identifying the relationship between the forces.

it may be easier to draw the vectors on a graph.

 

[thugg]

yea, I am really not remembering this though lol, just started doing this type of problem

 

[z-component]

I don't think a graph is necessary though. Just draw the x and y components of each force. Since T2 is already horizontal on the x axis, you don't need to split it up into x and y because it's all x and no y. That, of course, depends on where you draw your axes.

 

[thugg]

ok, but how exactly do you solve it

 

[gnpatterson]

Since we're not supposed to make it too easy for you. You should draw T1 as a horizontal part and a vertical part, since you know all the forces add up to zero you should be able to work out what the vertical part of T1 is hence T1 hence the horizontal part of T1 hence T2 end of question

For the second question it is a very similar setup just different angles and forces and all you have to do is know how the coeff of friction is defined. If you do the question with g kept as a symbol you will find it cancels out.

 

[thugg]

hmm still kinda confused, any chance you could show me step by step how to solve it


like how do you resolve T1 and T2 to get values using components...like i know the 20 has components of x = 0, and y = -20 right? but how do u get values with the 30 degree angle?