Solve Physics Homework: Forces & Friction | Get Expert Help

[koralex90]

I am having trouble solving this for my physics homework. Please help with these two problems!

http://img151.imageshack.us/img151/5049/scan1wd3.jpg

I just don't know where to start... please guide me..

 

[OlderDan]

For #7, draw the string attached to the hook using the angles given. Assume the picture hangs evenly and the strings are attached to the picture symmetrically so each end of the string supports the same weight (this is implied by the stated angles). The weight of the picture is supprted by the vertical components of the tensions. The horizontal components of the tension pull inward on the edges of the picture.

For #8 draw a free body diagram for each mass. Since the pulley has no mass, the tension in the string is uniform. Each mass will move the same distance with the same speed and the same magnitude of acceleration. You should be able to write two equations involving the unknown tension and the unknown acceleration, and solve them simultaneously for both variables.