Weight is a measure of the force of gravity acting on an object. According to Newton's laws of motion, force is directly proportional to both mass and acceleration, and the equation for force is F = m * a, where m = mass and a = acceleration.
Answer:
Her displacement is 35 feet. Her distance is 75 feet.
If she walks 20 ft N, 35 ft E, and 20 ft S, it makes a rectangle with one missing side, which is 35. Her displacement is therefore 35, and 20 plus 35 plus 20 equals 75, which is the distance she walked.
Hope this helps!
Answer:
The motion of a simple pendulum is very close to Simple Harmonic Motion (SHM). SHM results whenever a restoring force is proportional to the displacement, a relationship often known as Hooke's Law when applied to springs. Where F is the restoring force, k is the spring constant, and x is the displacement.
where θ is the angle the pendulum makes with the vertical. For small angles, sin(θ)∼θ, which would then lead to simple harmonic motion. For large angles, this approximation no longer holds, and the motion is not considered to be simple harmonic motion.
La visualización molecular significa mirar modelos moleculares para explorarlos y comprenderlos. La visualización molecular no implica necesariamente el modelado molecular, lo que significa crear modelos moleculares o cambiar la composición o las configuraciones de los modelos existentes.
With almost all substances . . .
-- when you cool them, their electrical resistance decreases.
-- If you make them even colder, their resistance decreases more.
-- If you make them even colder, their resistance decreases more.
-- If you make them even colder, their resistance decreases more.
-- If you keep making them colder, their resistance keeps decreasing,
but it never completely disappears, no matter how cold you make them.
But with a few surprising substances, called 'superconductors' . . .
-- when you cool them, their electrical resistance decreases.
-- If you make them even colder, their resistance decreases more.
-- If you make them even colder, their resistance decreases more.
-- If you make them even colder, their resistance decreases more.
-- If you keep making them colder, then suddenly, at some magic
temperature, their resistance COMPLETELY disappears. It doesn't
just become small, and it doesn't just become too small to measure.
It becomes literally totally and absolutely ZERO.
If you start a current flowing in a superconducting wire, for example,
you can connect the ends of the wire together, and the current keeps
flowing around and around in it, for months or years. As long as you
keep the loop cold enough, the current never decreases, because
the superconducting wire has totally ZERO resistance.
Did somebody say "What's this good for ? What can you do with it ?"
1). Every CT-scan machine and every MRI machine needs many
powerful magnets to do its thing. They are all electromagnets, with
coils of superconducting wire, enclosed in containers full of liquid helium.
Yes, it's complicated and expensive. But it turns out to be simpler and
cheaper than using regular electromagnets, with coils of regular plain
old copper wire, AND the big power supplies that would be needed
to keep them going.
2). Resistance in wire means that when current flows through it,
energy is lost. The long cables from the power-generating station
to your house have resistance, so energy is lost on the way from the
generating station to your house. That lost energy is energy that the
electric company can't sell, because they can't deliver it to customers.
There are plans to build superconducting cables to carry electric power
from the producers to the customers. The cables will be hollow pipes,
with liquid helium or liquid hydrogen inside to keep them cold, and
something on the outside to insulate them from the warmth outside.
Yes, they'll be complicated and expensive. But they'll have ZERO
resistance, so NO energy will be lost on its way from the generating
stations to the customers. The power companies think they can
build superconducting 'transmission lines' that will cost less than
the energy that's being lost now, with regular cables.
