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Gravity
One of the four fundamental interactions, gravity is responsible for the fact that any objects with mass attract one another. According to general relativity, it is a space time curvature, but according to quantum mechanics it is the result of exchanges of virtual gravitons.
4,784 Questions
What is a free-falling body object?
A free-falling body is an object in motion under the sole influence of gravity, with no other forces acting upon it. During free fall, the object only experiences the force of gravity causing it to accelerate downward at a rate of 9.8 m/s^2 near the Earth's surface.
How much work is done in lifting a 50kg crate a vertical distance of 10 meters?
Potential Energy is given by the fourmulai PE=MGH where M=mass in kilos, G=the force of gravity in Netwons (9.8N) and H=height in meters. So 50*9.8*10=4900joules. A Watt is a unit of power that =1 joule per second. So 4900 joules divided by 5 seconds = 980 Watts, not allowing for losses due to friction etc.
Does gravity or force affect the way a basketball goes in a hoop?
Everything the basketball does after it leaves the hand is the result of
the forces acting on it and its velocity achieved from the hands launching it. The force that acts on the basketball is the force of gravity.
What is the acceleration due to gravity when a body reaches the ground?
The acceleration is still 9.8 m/s2 but the force applied by gravity is counteracted by the ground.
When we work this kind of problem, we always ignore air resistance, mainly because
it's complicated, we're not exactly sure how to handle it, and if we included it, then
the complete answer would surely confuse everybody.
Ignoring air resistance, and considering gravity only, the ball tossed straight up
would have quite a bit more hang-time on Venus than on Earth, i.e. it would stay
up longer and hit the ground later. The reason is that the acceleration of gravity on
the surface of Venus is 9.7% less than it is on Earth, so the ball would slow down
less drastically on the way up, reach a higher peak, and accelerate less vigorously
on the way down.
Now, a word about why we were so desperate to ignore air resistance: The
atmospheric pressure on the surface of Venus is 93 times the atmospheric
pressure on the surface of the Earth, and the temperature there is over 850° F.
If we're not exactly sure how to account for the effects of air resistance on Earth,
we definitely don't know what allowances to make for air on Venus.
"g" typically refers to the acceleration due to gravity, which is approximately 9.81 m/s² on Earth. It can also represent the universal gravitational constant in physics, equal to 6.674 × 10^-11 m³ kg^-1 s^-2.
What is pushing upwards on your body while you are standing still?
That's an excellent question.
As a student of Physics, you know that in order for your body to be not accelerating,
the forces on you have to add up to zero. You know that the force of gravity is pulling
you down, and you want to know what other force there is that's canceling out gravity,
so that they really do add up to zero.
The answer is:
It's the force of the floor pushing up on the bottom of your feet, with a force that's
exactly equal to your weight.
You can measure that force like this: Put a tiny mirror on the floor. Then take the
bathroom scale, turn it over, and set it down on the floor upside down, so that
you can read the numbers in the tiny mirror on the floor. Carefully stand up on
the bottom surface of the scale. Now the scale is measuring the floor's upward
force on the bottom of your feet. What does it read ? See ? What did I tell you.
Anther perfectly good way to think about this:
The forces of gravity always work in pairs. Two masses always attract each other
with equal forces. The force that attracts you toward the center of the Earth is
what you call "your weight on Earth".
Nobody every talks about the other one ... the force that attracts the Earth
toward the center of you. The two forces are equal. It's perfectly correct to
call the other one "the Earth's weight on you", and you just measured it with
the upside-down bathroom scale.
How does weight differ depending on gravity?
Weight, mathematically speaking, is just mass times acceleration due to gravity. Mass is inherent in the object being weighed, and does not change. However, gravity can change (albeit very slightly) even on different points on the earth's surface. And comparing the earth's surface to that of other planets, gravity changes radically due to the difference between Earth's mass and that of other planets. So the greater gravity is, the greater the weight of a particular object will be. This explains the difference between weights of an object on the earth versus that on other planets -gravity is different on different planets. It also explains why comparing the weights of two objects at the same point on the earth's surface shows the difference in the mass of the two objects: the acceleration due to gravity is the same, so that masses are the only things that change.
What is formula of specific gravity?
Specific gravity of urine is a measurement of the concentration of urine. The higher the specific gravity, the more concentrated urine is. The measurement is similar to osmolarity. This measurement is used in drug testing to see if someone drank a lot of water before the drug test in an attempt to dilute drug metabolites.
What are the examples in which centre of gravity lies outside the object?
A centre of gravity is outside a single body where that body is shapde in such a manner as to cause that. For example, the COG of a horseshoe is not inside the horseshoe metal, but in the middle between the two sides of it, because the mass on either side of that point balances around it. A bar stool has a COG outside itself, since the same effect applies.
How do the direction of a car's velocity and acceleration compare when the car is slowing down?
When a car is slowing down, the direction of its velocity and acceleration are opposite. The car's velocity is in the direction of its motion, while its acceleration is in the opposite direction, which causes the car to decelerate.
Is your centre of gravity around your pelvis when standing up?
If you are a woman, yes. If yo are a man, no - it is across your chest.
Why is it difficult to walk on sand if you are wearing pointed heels as compared to flat shoes?
Because flat shoes have a much wider base than pointed heels so they spread your weight out more, to you walk more on top of the sand, like snowshoes. Whereas pointed heels have a very narrow base that causes you to sink into the sand a bit more, making it a little like walking in quicksand.
How high does it go when a baseball hits nearly straight up into the air with a speed of 22ms?
Ignoring air resistance, a baseball hit at any angle ... so long as the vertical
component of its velocity is 22 m/s ... will top out at 24.7 meters above the
height of the bat before it begins to fall.
What happen to the potential energy if its height increases?
If the height of an object increases, its potential energy also increases. This is because potential energy is directly proportional to the height of the object above a reference point, such as the ground. As the object is raised to a higher position, it gains more potential energy due to the increased distance it can potentially fall from.
When was telekinesis first discovered?
The concept of telekinesis has been around for centuries in various cultures and belief systems. However, the term "telekinesis" itself was coined in the late 19th century as a way to describe the psychic ability to move objects with the mind.
What would happen if gravitational force is not there?
If gravitational force didn't exist, then space would be full of hydrogen atoms
wandering aimlessly, having roughly uniform density everywhere.
Stars wouldn't exist, since the gas in space would have never clumped together.
Almost no atoms with nuclei heavier than hydrogen would exist, since they had
never been fused in the interior of stars.
Rocks would not exist, since no heavy elements had ever been synthesized in stars.
But if any did, they would wander through the universe in straight lines at constant
speeds, just like the hydrogen atoms, until they chanced to hit something. Then
they would either stick together, bounce off, or shatter.
Nothing would orbit anything, be attracted to anything, or have its path influenced
by anything with which it didn't collide.
As gravity collapses the cloud to form a protostar, the temperature and luminosity both increase. The increase in temperature is due to the compression of material, causing the protostar to heat up as energy is released. The increase in luminosity is a result of the protostar radiating this energy.
Is it possible that Gravity Comes from the Atom?
It's certainly true that there is a mutual gravitational force between atoms.
However, there are also mutual gravitational forces between and among
electrons, protons, neutrons, neutrinos, and particles in a plasma, none of
which are atoms. So it looks like there don't have to be any atoms around
in order to have gravitational force.
Why does gravity stop when out of earth's atmosphere?
Gravity does not stop outside the Earth's atmosphere. Gravity's range is theoretically infinite, so you will never be free of its influence. Every object has gravitational attraction for every other object in the universe. The force of that attraction is greater for objects with greater amass, and is gets less as the distance between the two increases.
The only way to not notice gravity's influence is to be in free fall. They you don't have anything opposing your movement toward the large attracting object (the earth) and you don't feel the attraction (the weight). As such weightlessness is experienced by astronauts in a spacecraft in orbit, so it is in free fall.
Is gravity is example of physics?
Gravity is an example of a force of nature being studied by physics. Physics is a human endevour to help increase our understanding of the natural world. To describe nature we have theories; for example we have the Theory of Gravity to explain gravity.
Is a one pound mass a slug on earth?
No, a one pound mass is not equivalent to one slug on Earth. One pound is a unit of force, while one slug is a unit of mass. On Earth, one pound of force is approximately equivalent to the weight of 0.0311 slugs of mass.
Which 2 factors determine gravitational attraction between 2 objects?
The two factors that determine the gravitational attraction between two objects are their masses and the distance between their centers. The greater the mass of the objects, the stronger the gravitational force, and the closer the objects are to each other, the stronger the gravitational attraction.
Is there such thing as a gravity machine?
There is no such thing as a gravity machine in the sense of a device that can manipulate or control gravity. In theory, if a gravity machine were to exist, it would require a significant amount of energy and be beyond current scientific understanding and technological capabilities.
Is there no gravity in Arizona?
As far as we're able to tell, gravity is present everywhere in the Universe.
It's certainly present everywhere on Earth, and the gravitational forces that
attract the earth and any object on it toward each other have essentially
the same strength, no matter where on earth the object happens to be.
