- #1
trew
- 19
- 0
- Homework Statement
- as below
- Relevant Equations
- as below
So I let x be the distance from P.
I then considered moments about R and got this:
1) (40g)(x-3) = 40gx - 120g and this is anticlockwise
2) (30g)(0.5) = 15g and this is anticlockwise
3) (2.5g)(2) = 5g and this is clockwise
And then by equating clockwise and anticlockwise I get this:
40gx - 120g + 15g = 5g
40gx = 110g
x = 110/44
x = 2.75m
But the mark scheme says this is wrong? They've got it as 3.25m. This is what they used as moments about R:
(40g)(x-3) + (2.5g)(2) = (30g)(0.5)
I don't get how they can consider the boy and the box Q to be on the same side??