Answer:
the location of 160 N from end E is 25mm
Explanation:
given:
A uniform plank of weight 100 N is 2000 mm long
and rests on a support that is 400 mm from end E
find:
At what distance from E must a 160 N weight be placed in order to balance the plank?
160 N
|---x--->|
100N \|/
======================||======================E
Δ---- 400mm---->|
|<---------------------------- 2000mm --------------------------->|
to determine the location of 160N load in order to balance the plank,
you have to take moment at support Δ.
note:
the 100 N is located at the center of a plank.
the distance of 100N from support = (2000 / 2) - 400 = 600mm
∑moment at Δ = 0
0 = -100 N (600mm) + 160 N (400-x)
0 = -60000 N.mm + 64000 N.mm - 160x N.mm
0 = 4000 - 160x
160x = 4000
x = 4000/160
x = 25 mm
therefore,
the location of 160 N from end E is 25mm
