1 Answer

Mike Bovenlander · Answer 1 · 2021-01-17T07:36:24+0000

Answer: a) Moment = 200N.m

b) F = 500N

Step-by-step explanation: Moment or Torque is the tendency of a body to rotate because of an aplplied force. It can be calculated as

$\tau = F.r.sin\theta$

F is force applied

r is distance from the force to the point of rotation

θ is the angle formed between force and distance

a) Since F and r are perpendicular, θ=90°, sin90° = 1, so

$\tau=F.r$

$\tau=100(2)$

$\tau=$ 200

Torque caused by weight of the barrier at the pivot is 200N.m

b) Counterweight has the same torque as pivot:
$\tau=$ 200

So, to find Force necessary to balance the weight:

$\tau=F.r$

$F=(\tau)/(r)$

F=(200)/(0.4)

F = 500

It is necessary a force of 500N from the counterweight to balance the weight.

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