Which of the following are conditions required for static equilibrium? Select TWO answers. Elimination Tool A Linear Momentum = →p=0. B:Angular Momentum = →L=0. C:Change in Energy = ΔEtotal=0. D: Net Force ≠0.

The correct answers are Choices 'A' and 'B'.

Explanation:

The correct answers are Choices 'A' and 'B'.

Static equilibrium means that the object is not moving relative to a given frame of reference.

Choice 'A' Linear Momentum = →p=0

is required. "Not moving" means the velocity  

v must be 0(otherwise the object would be moving across the reference frame), so an object's linear momentum (which is its mass times its velocity) must be 0.

Choice 'B' Angular Momentum = →L=0 is required. "Not moving" also means that the object can not be rotating or spinning inside the reference frame, which means the rotational velocity ω must be 0. So an object's angular momentum (which is its mass times its rotational velocity) must be 0 .

Choice 'C' Change in Energy  is true (this is known as conservation of energy), but it is not a requirement of static equilibrium because "not moving" is not the same as "isolated."

There are many forms of energy, many of which are not related to movement. For example, a light bulb in a stationary lamp is in static equilibrium, but if the light is turned on .

Similarly, when you add gasoline to your car at a gas station, the car must be in static equilibrium, but the addition of the gasoline from outside the car changes the Total Energy of the car.

Choice 'D' Net Force ≠0 is a non-equilibrium condition because by Newton's second law of motion, so any non-zero net force will cause an acceleration, and acceleration is not a state of static (or dynamic) equilibrium.

find the sum of the two horizontal vectors and the sum of the two vertical vectors

isoceles right angled triangle

snell's law

refractve index = sin incidence / sin refraction