The force of gravity
acts upon a high speed satellite to deviate its trajectory from a straight-line inertial
What causes a satellite to move?
A satellite orbits Earth
when its speed is balanced by the pull of Earth’s gravity
. Without this balance, the satellite would fly in a straight line off into space or fall back to Earth. … It moves in the same direction and at the same rate Earth is spinning.
What factors affect the orbital speed of a satellite?
As seen in the equation v = SQRT(G * M
central
/ R),
the mass of the central body (earth) and the radius of the orbit
affect orbital speed. The orbital radius is in turn dependent upon the height of the satellite above the earth.
How do satellites get their speed?
A satellite maintains its orbit by balancing two factors: its velocity (the speed it takes to travel in a straight line) and
the gravitational pull that Earth has on it
. A satellite orbiting closer to the Earth requires more velocity to resist the stronger gravitational pull.
Why do satellites not accelerate?
Why aren’t satellites increasing speed because
of gravitational acceleration
? Satellites orbiting the earth are experiencing almost as strong gravitation as we do, but they don’t hit the earth because of their velocity outwards and the earth’s curvature.
What forces act on a satellite in orbit?
Acting on the satellite are two forces:
gravity
, pulling the satellite toward Earth, and this centrifugal force, pushing the satellite away.
Why is a satellite like a falling object when it is in orbit?
The Short Answer: Satellites don’t fall from the sky because they are orbiting Earth. …
Gravity—combined with the satellite’s
momentum from its launch into space—cause the satellite to go into orbit above Earth, instead of falling back down to the ground.
What happens when satellite speeds up?
If the satellite is moving too quickly then the gravitational attraction between the Earth and the satellite is too weak to keep it in orbit. If this is the case,
the satellite will move off into space
. This occurs at speeds around or above 11,200 metres per second (m/s).
What force causes planets to orbit?
First,
gravity
is the force that pulls us to the surface of the Earth, keeps the planets in orbit around the Sun and causes the formation of planets, stars and galaxies.
What does orbital speed depend on?
The mean orbital speed of the object depends only on
the Earth’s mass and the semi-major axis (half the longest diameter) of the object’s orbit
. However, the orbital speed changes depending on where in the orbit the object is. It will be greatest when closest to Earth and least when furthest from Earth.
How fast is the earth spinning?
The earth rotates once every 23 hours, 56 minutes and 4.09053 seconds, called the sidereal period, and its circumference is roughly 40,075 kilometers. Thus, the surface of the earth at the equator moves at a speed of 460 meters per second–or roughly
1,000 miles per hour
.
Do satellites flash?
Many satellites do not have a constant brightness, they give off flashes at (usually) regular times. This flashing behavior is caused by
the rotation of the satellite around its rotation axis
. The satellite’s metallic surfaces act as mirrors for the sun (specular reflection).
Do satellites stay in orbit forever?
A satellite has a useful lifetime of
between 5 and 15 years depending
on the satellite. It’s hard to design them to last much longer than that, either because the solar arrays stop working or because they run out of fuel to allow them to maintain the orbit that they’re supposed to be in.
Are satellites constantly accelerating?
Indeed, a satellite
is accelerating towards the Earth due to the force of gravity
. … As such, the projectile will fall around the Earth, always accelerating towards it under the influence of gravity, yet never colliding into it since the Earth is constantly curving at the same rate.
What happens if a planet falls out of orbit?
Without any orbit,
Earth would likely go crashing directly into the sun
. That’s because our planet’s path around that big, bright star in the sky is what keeps Earth from being pulled in directly by the sun’s gravity. … It’s constantly falling toward the sun, but moving too fast to actually reach it.
Why do satellites not need fuel in orbit?
Satellite needs no fuel to move around a planet in a fixed orbit because
the gravitational force of attraction between the satellite and the planet provides the necessary centripetal force required to revolve around it
. … An astronaut inside a small spaceship orbiting around the earth cannot detect gravity.
What force keeps moon in orbit?
However, the reason the Moon stays in orbit is precisely because of
gravity —
a universal force that attracts objects. With the right combination of speed and gravity, satellites can fall around, instead of into, the body that they orbit.
Why do satellites eventually fall to Earth?
A satellite in space will eventually fall on the Earth
due to drag
. The atmosphere doesn’t just stop—it tails off gradually. By the time you get up to geostationary orbit, there are a few air molecules whose orbits are stable for thousands of years.
What happens if a satellite slows down?
If the satellite slows down it would
crash into the object it is orbiting
. If the satellite speeds up, it may spin off into space. The satellite could be knocked or moved closer or farther from the object it is orbiting.
What two forces affect the level of an object’s acceleration?
The acceleration of an object depends on two things—
the object’s mass and the size of the applied force
. The greater the force applied to an object, the more that object will accelerate; the greater the mass of an object, the less that object will accelerate.
How often do satellites fall to earth?
On average, a total of between 200-400 tracked objects enter Earth’s atmosphere every year. That’s
about one every day
! Thankfully human populations are rarely affected by things falling from the sky (from outer space). This is largely a numbers game.
Do satellites stay in one place?
Because the satellite orbits at the same speed that the Earth is turning, the
satellite seems to stay in place over a single longitude
, though it may drift north to south. … Satellites in geostationary orbit rotate with the Earth directly above the equator, continuously staying above the same spot.
How do you speed up orbiting?
Changing speed is one way to change the orbit of a satellite or make a satellite leave orbit. Speed can be changed by
increasing thrust to make a ship go faster
, or retroburning or aerobraking to slow it down.
What affects the speed of a planet’s orbit?
A planet’s orbital speed changes, depending on how far it is from the Sun. The closer a planet is to the Sun, the
stronger the Sun’s gravitational pull on it
, and the faster the planet moves. The farther it is from the Sun, the weaker the Sun’s gravitational pull, and the slower it moves in its orbit.
Why do things stay in orbit?
How Do Objects Stay in Orbit? An object in motion will
stay in motion unless something pushes or pulls on it
. … An object’s momentum and the force of gravity have to be balanced for an orbit to happen. If the forward momentum of one object is too great, it will speed past and not enter into orbit.
What force causes acceleration?
Acceleration and velocity
Newton’s second law says that when
a constant force acts on a massive body
, it causes it to accelerate, i.e., to change its velocity, at a constant rate. In the simplest case, a force applied to an object at rest causes it to accelerate in the direction of the force.
Do satellites travel at different speeds?
No,
satellites that orbit at different altitudes have different speeds
. … These satellites travel at about 11,000 kilometers per hour (7,000 miles per hour). The moon, at about 380,000 kilometers from the earth (240,000 miles) only travels about 3,700 kilometers per hour (2,300 miles per hour).
How many dead satellites are in space?
There are
more than 3,000 dead satellites
and rocket stages currently floating in space, and up to 900,000 pieces of space junk ranging from 1 to 10 centimetres in size — all large enough to be a collision hazard and a potential cause for disruption to live missions.
At what altitude do satellites burn up?
Technically, objects in low-Earth orbit are at an altitude of
between 160 to 2,000 km (99 to 1200 mi) above the Earth’s surface
. Any object below this altitude will being to suffer from orbital decay and will rapidly descend into the atmosphere, either burning up or crashing on the surface.
What two factors keep Earth in orbit and around the sun and the moon in orbit around Earth?
Newton concluded that two factors
—
inertia and gravity– combine to keep Earth in orbit around the sun, and the moon in orbit around Earth.
Why does an astronaut weigh less on the moon?
The Earth’s Moon has considerably less mass than the Earth itself. Not only is the Moon smaller than the Earth, but it is only about 60 percent as dense as Earth. Thus,
the gravitational attraction on the Moon is much less than it is here on Earth
, and a person weighs less on the Moon.
How fast do satellites move across the sky?
The speed a satellite must travel to stay in orbit is
about 17,500 mph (28,200 km/h)
at an altitude of 150 miles (242 kilometers.) However, in order to maintain an orbit that is 22,223 miles (35,786 kilometers) above Earth, a satellite orbits at a speed of about 7,000 mph (11,300 km/h).
How do planes fly if the Earth is spinning?
First, as the Earth itself rotates, it takes
the air with
it (thanks, gravity!). That includes the air through which planes fly. At the equator, the Earth spins about twice as fast as a commercial jet can fly. That rate slows the closer you get to the poles, but regardless, it’s always going to be faster than a plane.
Why do we not feel the Earth moving?
But, for the most part, we don’t feel the Earth itself spinning
because we are held close to the Earth’s surface by gravity and the constant speed of rotation
. Our planet has been spinning for billions of years and will continue to spin for billions more. This is because nothing in space is stopping us.
Does Sun rotate?
The Sun rotates on its axis once in about 27 days
. This rotation was first detected by observing the motion of sunspots. … In fact, the Sun’s equatorial regions rotate faster (taking only about 24 days) than the polar regions (which rotate once in more than 30 days).
Do satellites have red lights?
They can be distinguished from aircraft because satellites do not leave contrails and
do not have red and green navigation lights
. They are lit solely by the reflection of sunlight from solar panels or other surfaces.
Do satellites have exterior lights?
Satellites don’t have exterior lights
. … When you spot a satellite, you are actually seeing reflected sunlight. The ISS has a huge array of reflective solar panels that reflect a lot of sunlight, making it easy to see. Unless you are spotting the super bright ISS, you need to be away from city lights.
Do satellites have bright lights?
The satellites don’t emit any light themselves
, said Samantha Lawler, an astronomer at the University of Regina. Instead, they’re visible because they reflect sunlight. “It’s like a train of stars moving together in a line.
Is it possible for an object to accelerate with constant speed?
The velocity vector is constant in magnitude but changing in direction. Because the speed is constant for such a motion, many students have the misconception that there is no acceleration. … For this reason, it can be safely concluded that
an object moving in a circle at constant speed is indeed accelerating
.
Can an object accelerate with constant speed?
Can an object accelerate if it’s moving with constant speed?
Yup
! Many people find this counter-intuitive at first because they forget that changes in the direction of motion of an object—even if the object is maintaining a constant speed—still count as acceleration.
Is it possible for an object to accelerate without speeding up or slowing down?
Since velocity is a speed and a direction, there are only two ways for you to accelerate: change your speed or change your direction—or change both. If you’re not changing your speed and you’re not changing your direction, then
you simply cannot be accelerating
—no matter how fast you’re going.
