IGCSE/GCSE/O & A Level/IB/University Student Forum

Qualification => Subject Doubts => GCE AS & A2 Level => Sciences => Topic started by: aiyla on October 05, 2009, 04:36:04 pm

Title: Physics Question help !
Post by: aiyla on October 05, 2009, 04:36:04 pm

this question i dont know how to solve it .. can any one please help me out ?

(http://i35.tinypic.com/wvrfv7.jpg)

http://i35.tinypic.com/wvrfv7.jpg
(thats the image if the above one is too small)

the question says " calculate the minimum force needed just to lift the spherical ball above the floor , the weight of the spherical ball is 50N
i did everything else on the drawing u can get the idea and the values required .

answer is F=26

the teacher said something about using equilibrium's second law .
sum of moment acting on the body= 0
clockwise moment = anti clockwise


can any one explain this question please ?

Title: Re: Physics Question help !
Post by: nid404 on October 05, 2009, 05:15:43 pm

kinda vague...astar will be able to help you

Title: Re: Physics Question help !
Post by: astarmathsandphysics on October 05, 2009, 07:10:25 pm

Will answer it when i get home.

Title: Re: Physics Question help !
Post by: aiyla on October 05, 2009, 07:15:02 pm

thanks alot <3

Title: Re: Physics Question help !
Post by: astarmathsandphysics on October 05, 2009, 09:01:01 pm

see attached image.

Take moments about A.

Applied force*(10+15)=50*sqrt(175) so applied force =50*sqrt(175) /25 =26.46N

Title: Re: Physics Question help !
Post by: aiyla on October 05, 2009, 09:12:10 pm

thanks astar, that was helpfull

Title: Re: Physics Question help !
Post by: astarmathsandphysics on October 05, 2009, 09:19:10 pm

mo probs. Keep 'em coming