Physic problem
Object A is connected to object B by a massless string that passes over a massless, frictionless pulley. Object A is on a frictionless 30degree incline. Object A's mass is 2,0kg. When object B falls 1,0m its velocity is 2,5m/s. What's the mass of object B?
I can't find a solution to this. I don't know how can I get the acceleration.
September 20, 2013
2 Comments • Newest first
[quote=cchpm]1. draw a free body diagram - object B should have mg going down, and tension going up. Object A should have mg going down, normal force in an angle, and tenstion in an angle.
2. write equation of x and y components
sum of F on B (down = positive)= mg - T = ma
sum on F on A on y (up = positive) = Tsin30 +Ncos30 -mg=masin30 (I think ... dont have a paper, so not sure if this is correct, but it should be something like this)
3. solve equations by equating T[/quote]
Doesn't work like that. I thought that was how you solve it as well. But I got it now though. Thanks for trying.
1. draw a free body diagram - object B should have mg going down, and tension going up. Object A should have mg going down, normal force in an angle, and tenstion in an angle.
2. write equation of x and y components
sum of F on B (down = positive)= mg - T = ma
sum on F on A on y direction (up = positive) = Tsin30 +Ncos30 -mg=masin30 (I think ... dont have a paper, so not sure if this is correct, but it should be something like this)
sum of F on A on x directiong (right = positive) =Tcos 30- Nsin30 = macos30 (again, not really sure about the signs & cos/sin, but should be similar/switched around)
3. solve equations by equating T
EDIT: let me do it on paper & see what happens.