You are Here: Home >< Maths

# M2 Question watch

1. Quesiton:

ABCD is a uniform square lamina of side 4m and mass 8kg. It is hinged at A so that it is free to move in a vertical plane. It is maintained in eqilibrium with B vertically below A by a horizontal force acing at C and a verticle force acting at D, each of magnitude F newtons.

Find the value of F?

Can anybody show me how they got an answer of 19.6N.

Cheers
2. (Original post by Revenged)
Quesiton:

ABCD is a uniform square lamina of side 4m and mass 8kg. It is hinged at A so that it is free to move in a vertical plane. It is maintained in eqilibrium with B vertically below A by a horizontal force acing at C and a verticle force acting at D, each of magnitude F newtons.

Find the value of F?

Can anybody show me how they got an answer of 19.6N.

Cheers

moments C.W. = moments A.C.W.
8g . 2 = F.4 + F.4
16g = 8F
F = 2g
F = 9.8 x 2
F = 19.6 N
Attached Images

3. Thanks, i never knew that rule
4. from what point are you taking the moments about?
5. A, as it's hinged from A
6. wouldnt it be then root(4^2 + 2^2) x 8g ? as thats the distance of A from 8g ?
7. moments = F . distance perpendicular
8. oh ok, i never knew that rule either! thanks

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: June 6, 2005
Today on TSR

Uni realities

### University open days

• University of Lincoln
Mini Open Day at the Brayford Campus Undergraduate
Wed, 19 Dec '18
• University of East Anglia
Fri, 4 Jan '19
• Bournemouth University
Wed, 9 Jan '19
Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams