Презентация - Equilibrium. State of balance

EQUILIBRIUM
State of balance

WHEN IS A BODY CONSIDERED TO BE IN EQUILIBRIUM?
First Condition: FORCES ARE BALANCED. (Translational Equilibrium) The body is not accelerating.

TRANSLATIONAL EQUILIBRIUM
Static Equilibrium
Dynamic Equilibrium
Objects at rest Acceleration = 0
Objects in motion Travelling at constant velocity Acceleration = 0

Hanging motionless
FREE BODY DIAGRAM
392 N
40 kg
(-9.8) = -392N

What is the tension in each rope?
Assume that the angle that each rope makes with the horizontal (600) is the same.

What is the tension in each rope?
FREE BODY DIAGRAM
1000 N

Determine the masses, and of the 2 objects shown below if the force exerted by the horizontal cable on the knot is 64 N.

torque
A measure of how effectively a force causes rotation

fulcrum
Point where the lever turns

Lever arm
The perpendicular distance from the fulcrum to the point where the force is exerted

Torque in real life

torque
Lever arm
force
 Torque θ  Angle F  Force l  lever arm

Rank the magnitudes of the torque that the strings exert on the beam (from largest to smallest). Indicate if any torques have equal magnitudes.

WHEN IS A BODY CONSIDERED TO BE IN EQUILIBRIUM?
Second Condition: THE OBJECT DOES NOT ROTATE. (Rotational Equilibrium) TORQUES (ROTATIONAL FORCES) MUST BE BALANCED.

WHEN IS A BODY CONSIDERED TO BE IN EQUILIBRIUM?
Sign Convention: Clockwise  negative direction Counterclockwise  positive direction The sum of torques must be zero.

A window washer stands (1.5 m from the left rope) on a uniform plank of mass 50 kg and length 5 m supported by 2 ropes attached at the ends of the plank. The window washer has a mass 100 kg. What is the tension in each of the ropes?

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A 3.0 m long beam with a mass of 100 kg is supported at each end. An 80 kg student stands 2.0 m from Support 1. How much upward force does each support exert on the beam?

Two men are carrying a 445 N girl using a 10 m beam. The beam has a weight of 200 N. How much force does each man exert?

CALCULATING THE CENTER OF MASS