1/3, the X value of the triangle is 19

Mass of the lamina is 16*10+9*5-9pi = 176.726

X values are 8 (rectangle), 4 (circle) and 19 (triangle)
160*8+45*19-9pi*4=176.726x=2021.9

x = 2021.9/176.726 = 11.44

got that answer a few times, should be correct unless i'm missing something

Reply 49

morgan-angharad

2

Original post by 4er4w

1/3, the X value of the triangle is 19

Mass of the lamina is 16*10+9*5-9pi = 176.726

X values are 8 (rectangle), 4 (circle) and 19 (triangle)
160*8+45*19-9pi*4=176.726x=2021.9

x = 2021.9/176.726 = 11.44

got that answer a few times, should be correct unless i'm missing something

Wouldn't X value for circle be 7 as it's 4+radius?

Reply 50

4er4w

Original post by morgan-angharad

Wouldn't X value for circle be 7 as it's 4+radius?

I interpreted the diagram to show that the radius is 4cm away from the line AE
Looking at it, it could just as easily show that the edge of the circle is 4cm away, even though the line 2cm lines are the same size as the 4cm lines.

That's a ridiculous diagram. Shame on WJEC

Reply 51

xPhoebex

1

So what's the answer for question 9? I had x= 11.44 and I think y= 5 once rounded

Reply 52

Sh4hid96

6

For the radius I had 3. The total distance was 10cm, then there was 2cm either side of the circle. 10-4=6. Then divided the 6 by 2 to give 3. Then used pi r squared and took it from there. Had 5cm dot on for y and for x I had 10.76 or 10.96. can't remember.

Reply 53

4er4w

Original post by xPhoebex

So what's the answer for question 9? I had x= 11.44 and I think y= 5 once rounded

if you take the x value of the circle to be 4 then yeah, 11.44
if you take it as 7, then something else, possibly 10.96
i really don't know which is right

Reply 54

xPhoebex

1

How did everyone work out question 4? Do you just times the mass by the x coordinate to find x then times the mass by the y co-ordinate to find y I got really confused 😳

Reply 55

4er4w

Original post by xPhoebex

How did everyone work out question 4? Do you just times the mass by the x coordinate to find x then times the mass by the y co-ordinate to find y I got really confused 😳

It's just a lamina question.

Call the points 1 2 3 4

1*x+2*x+3*x+4*x=(1+2+3+4)*x

where 1,2,3,4 denotes their mass and x denotes their x values

same for y

Reply 56

xPhoebex

1

Original post by 4er4w

It's just a lamina question.

Call the points 1 2 3 4

1*x+2*x+3*x+4*x=(1+2+3+4)*x

where 1,2,3,4 denotes their mass and x denotes their x values

same for y

Fab thankyou 🎉 that's what I did