any one like physics

i know thats a dumb question because i dont think physicist even like it but i was wondering if there is anyone who could maybe help me with some physics?

its not hard physics its just the one physics class i need for my major and im having a little trouble figuring out a problem.
my professor gave us a question that he said is going to be bonus and he said we need to practice it because there is two ways to solve it and im having trouble. he gives the answers but i cant figure out how to work it out.

this is the problem with the answers:

Here are a few incline plane problems to help you practice for the bonus part of the final exam.This can be solved two different ways. One way involves using Newton's laws and kinematics. The other way involves using Newton's laws and conservation of energy. Try to solve them both ways.

A 5.0 kg block is projected at 5.0 m/s up a plane that is inclined at 30 degrees with the horizontal. How far up along the plane does the block go if the coefficient of kinetic friction between the block and the plane is 0.40? (Ans: 1.5 m) If the block then slides back down against the frictional force, what is the block's speed when it reaches the original projection point? (Ans: 2.13 m/s)


any help? i know its asking a lot but id appreciate it!

 

...for the kinematics solution, ..I would establish a coordinate axes, say, w/ the "x" axis running along the surface of the inclined plane, then, you know that the "motion" is constrained to that plane... you will need to formulate an analytical solution for essentially equations of motion and F=Ma in both axes ("x" and "y"), ...again, with the "x" axis we have motion, ..and we will compute the acceleration due to the forces acting on the object in that plane, ..then plug in that acceleration into your rectilinear equation of motion in that plane...

 

Well I'll give that a shot but normally I just leave the coordinate plane alone and draw the image based inside it because it makes it easier to find the forces in the "y" direction like the weight and the force of gravity. I've never tried it with the x-axis going along the surface, I'll have to try that out and see how it goes.

Thanks for the advice

 

...it simplifies the problem... by making one axis (call it "x", or whatever you want) along the direction of travel, ...we eliminate one unknown, that being we know (assume) there is no acceleration occuring on the other axis (call it "y" axis, ...so long as it's perpendicular to the "x" axis)... so using this coordinate system, draw your free body diagram and project the forces into this system... first you have to find the acceleration (hint, ..it will be a constant acceleration) of the object given the conditions, ..then you can figure out the distance of travel with a simple rectilinear equation of motion...

in going through engineering skrool, we had to spend a lot of credit hours on physics, ...and one thing that stands out from that experience was that simplification of the problem in manners such as this are key... the professors loved to tease the problem solving ingenuity of the students

 

ohhh i see what you mean now. and yes simplification is key, its just hard to see it sometimes when you've been doing it one way the whole time.
and it does seem like physics professors, aside form math professors, are mainly the ones who test the problem solving capabilities of their students. especially a low level physics class because they know they are way smarter than the students so they decide to really test them to see how far their thinking will go lol sometimes it seems like the professor likes to watch us stare at the board blankly while trying to figure out which formula to use.


people like me, who hate physics, are not willing to spend much time on the subject lol im just trying to get out of this one class because its the only one i need.

 

..yep, ...physics professors can be very wily...

hopefully the challenge will improve your enjoyment of it!

 

Lol "enjoyment" of physics.