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Transcript Equilibrium

The Greek letter Tau
The Physical Study of Balance
Sum of forces is zero
Tendency to rotate is zero
the effectiveness of a force in causing rotation
on a rigid object
also called moment of force
Which of the following forces will
effectively rotate the beam at point O?
Which of the following forces will
effectively rotate the beam at point O?
Which of the following forces will
effectively rotate the beam at point O?
Which of the following forces will
effectively rotate the beam at point O?
The amount of force perpendicular to the lever arm.
The distance of the force from the pivot point.
Illustrate all the forces and the lever arm for
each.
Torque is the product of force and its distance
from the point of rotation.
Force and the lever arm must always be
perpendicular.
Establish the point of rotation.
Equate the sum of forces to zero.
Equate the sum of torques to zero.
A 50.0 N uniform beam, 10.0 m in length, is suspended
on a support as shown. If the fulcrum divides the beam
into the ratio of 2:3, where should a 6.00 kg object be
placed to balance the beam?
x
In a Singkil dance, two men are carrying a princess on
a bamboo pole that is 5.00 m long and weighs 200.0
N. If the princess weighs 425 N and sits 1.50 m from
one end, how much weight must each man support?
(Follow up)
Where should the princess sit so that one man
supports her with a force twice that of the other?
?
Consult page
117 of your book
and read
Practice
Exercise 5.8
Rx
lRx
w
Ry
f
1m
lw
A uniform 50.0 N ladder
rests on a frictionless wall
as shown. What
minimum coefficient of
friction is needed on the
ground to prevent it from
slipping?
5m
2m
A uniform aluminum beam 9.00 m long, weighing 300 N,
rests symmetrically on two supports 5.00 m apart. A boy
weighing 600 N starts at point A and walks toward the
right.
From your diagram, how far beyond point B can the boy
walk before the beam tips?