A 6kg box is placed on a 32degree frictionless ramp. Find accel. of the box.

[Kaxa2000]

I have the solution to the problem but I don't get the part how you rotate the axes and then solve from there.

For example in the x direction
Fx = max

+mg sin32 = max

Fx = Force in x direction
ax = acceleration in the x direction

Can someone explain this?

 

[Kurdt]

You're taking the component of the weight vector down the ramp. That is the force that accelerates the box.

 

[tiny-tim]

Welcome to PF!

Hi Kaxa2000! Welcome to PF!

You're taking the component of the weight vector down the ramp. That is the force that accelerates the box.

I'll just add that you shouldn't think of it as a rotation …

everything stays as it is, and you simply choose to take components in whatever direction is most convenient …

for example, you could use horizontal and vertical components …

but that would give you two equations , while choosing along-the-ramp and normal gives you only one relevant equation, which is much easier!