Force and pressure

Physics

strain is

the ratio of the change in length to the original length

If an object is stretched beyond the elastic limit, it enters the _______ on an applied force versus
elongation graph for a typical meta

plastic region

Stress is

applied force per cross-sectional area

The maximum elongation of a typical metal is reached at the breaking point

True

An object floats on a fluid if its [average] density is less than that of the fluid

True- In the question it uses average bc of ships metal is heavier than water but bc there of the air its average density

The maximum force that can be applied without breaking a material is called the breaking force.

False- Its called “breaking point”

State Bernoulli's principle.

Where the velocity of fluid is high, the pressure is low; and where the velocity is low, the pressure is high.

State Pascal's Principle

If an external pressure is applied to a confined fluid, the pressure at every point within the fluid increases by that
amount

Define specific gravity.

The specific gravity of a substance is defined as the ratio of the density of that substance to the density of water at
4.0°C

State the conditions for static equilibrium.

(1) The net force acting on the object must be zero.
(2) The net torque acting on the object must be zero.

State and describe the three phases of matter.

The three common phases of matter are solid, liquid, and gas. A solid maintains a fixed shape and a fixed size; even if
a large force is applied to a solid, it does not readily change in shape or volume. A liquid does not maintain a fixed
shape - it takes on the shape of its container - but like a solid it is not readily compressible, and its volume can be
changed significantly only by a very large force. A gas has neither a fixed shape nor a fixed volume - it will expand to
fill its container

State Archimedes Principle

The buoyant force on an object immersed in a fluid is equal to the weight of the fluid displaced by that object.

State Archimedes' Principle.

It is the difference between the actual pressure and the atmospheric pressure.

What is meant by gauge pressure?

It is the difference between the actual pressure and the atmospheric pressure.

The region from the origin to the elastic limit on an applied force versus elongation graph
for a typical metal under tension is referred to as the

elastic region.

If the net force on an object is zero, does the net torque on the object also have to be zero?

No. For example, the object might be subjected to two equal and opposite forces that are not along the same straight
line. This would produce a torque, but the net force would be zero

Tensile Stress

force pulling outward

compressive stress

force pushing inward

Shear stress

opposite forces causing a tear

Tightrope walkers often employ a long pole to help them retain their balance. What advantage is there to using a very flexible pole so that the ends droop?

-If the ends droop the center of mass is lowered as the center of mass lowers its a lot easier to keep balance

-With a really long pole we get and increased I value , so then it takes more force to tilt the person and the pole

If the net torque on an object is zero, does the the net force on the object also have to be zero?

No! if you push something forward its being moved but not spilling so the net force is more then zero but the toque is zero