Why are Astronauts weightless in Space?
Astronauts orbiting the Earth, often experiences sensations of weightlessness. These sensations though in Space but could slightly be felt in some way on Earth.
Similar sensation is felt by anyone who has been temporarily suspended above the seat on an amusement park ride. Not only are the sensations similar, (Astronauts and Roller coaster riders), the causes for those sensations are similar too.
SYNONYMOUSLY,
Technically, a scale doesn't measure one's weight. Despite the result of one's weight displayed from a weighing scale.
While we use a scale to measure one's weight, the scale reading is simply a measure of the upward force applied by the scale to balance the downward force of gravity acting upon an object.
When an object is in a state of equilibrium, these two forces are balanced. The upward force of the scale upon the person equals the downward pull of gravity (The weight). In such instance,the scale reading equals the weight of the person.
However, if the person stands on the scale and bounces up down, the scale reading undergoes instantaneous change.
With the bouncing motion, the body is accelerating.
During the acceleration periods, the upward force of the scale changes.
Absolutely Not!!! You weigh as much or as little as you normally to. The scale reading changes but the scale doesn't measure your weight. The scale is only measuring the external contact force that is being applied to your body.
With respect to Astronauts' weightlessness in space, Gravity in space is of course the driving factor responsible.
A common misconception o what keeps the moon in it's orbit around the Earth? Or what keeps the Earth in orbit around the Sun or perhaps, what holds galaxies together.
Answer is GRAVITY
Generally, larger planets have a greater gravitational force than smaller ones.
Earth's gravity keeps satellites in orbit. Radio signals can be bounced off them so that telephone calls, television programmes and other communications can be sent rapidly around the world.
If you built a tower on the Earth 370km (230 miles) high, about as high as the Space Station's orbit, the gravity on top of the tower would be almost as strong as if you were on the ground.
The role of gravity isn't just peculiar to Astronomy. Boxers aim not to be knocked down! Thus, they try to keep wide-legged stance to give themselves a low centre of gravity and maximum stability.