Maths Mechanics M1 HELP!

[nehaoscar]

Please look at question number 4 in the paper in the attached file.

For part one, you can find X by resolving horizontally so 40cos60=xsin30
My question is, why can you not get the correct answer by resolving vertically?

The body is in equilibrium, so shouldn't all (vertical and horizontal) components result to zero?
In this case, the vertical components do not result to zero... why not?
Please help!

 

[manar4]

Please look at question number 4 in the paper in the attached file.
View attachment 51586
For part one, you can find X by resolving horizontally so 40cos60=xsin30
My question is, why can you not get the correct answer by resolving vertically?

The body is in equilibrium, so shouldn't all (vertical and horizontal) components result to zero?
In this case, the vertical components do not result to zero... why not?
Please help!

hi
when u use the vertical method u have to take the normal reaction force into consideration so it will be R+40sin(60)+Xsin(30)=150 where 150 is the weight of the block.
this method is harder as u have to unknown values the normal reaction force and X so i prefer doing it with the horizontal method cuz u have only one unkown value which is X.
If u did not understand i can repeat it for u.

 

[nehaoscar]

hi
when u use the vertical method u have to take the normal reaction force into consideration so it will be R+40sin(60)+Xsin(30)=150 where 150 is the weight of the block.
this method is harder as u have to unknown values the normal reaction force and X so i prefer doing it with the horizontal method cuz u have only one unkown value which is X.
If u did not understand i can repeat it for u.

Oh i see! I was just assuming R to be equal to weight and somehow just ignoring it!
Thankyou sooo much!

 

[nehaoscar]

https://www.xtremepapers.com/community/threads/maths-mechanics-m1-help.40815/ Please check this question too and please help!