The reason an astronaut in an earth satellite feels weightless is that the astronaut is falling.
Option a
<u>Explanation: </u>
The other options except Option is not applicable since the gravitational force is a long range force, in which the satellite revolves very close to the surface of the Earth where the gravity is felt.The zero weight experienced by the astronaut in a satellite is due to the earth pulling along with satellite. Due to gravitational force of the Earth,the astronaut falls freely .
But why not the satellite comes down due to gravity when its launched in space. The fact is that the satellite is launched with velocity of tangent direction and it is very high. The centripetal force balances the gravity.
In the absence of gravity, t<span>he rocks and debris
would never accrete into a planet. (B)
Also by the way, it wouldn't matter much, because
there wouldn't be a star to orbit around, AND orbits
wouldn't exist either.</span>
Answer:
The driving force for (a) heat transfer is temperature difference. (b) electric current is voltage difference. (c) fluid flow is pressure or hydraulic head difference.
Explanation: (a) The driving force for heat transfer is temperature difference. Heat transfer between two mediums is possible only if the two mediums are at different temperature, the higher the temperature, the higher the heat transfer.
(b) The driving force for electric current is voltage difference. Voltage difference is defined as the potential difference in charge between two points in electrical field. For electric current to occur,the voltage must be high.
(c) The driving force for fluid flow is pressure difference or hydraulic head difference. For fluid to move upward,it requires energy.
Answer:
A 'kink' in the glass tube which breaks the mercury as it contracts, storing the highest temperature reading. The glass tube is shaped like a lens to magnify the thin mercury thread. Shaking the thermometer resets the mercury back into the bulb.
The quantity that is calculated from the product of the force and the distance traveled due to the force is called work. It has SI units of Joules (J) which is equivalent to Newton-meter (N-m). It is the energy that happens when an object is being moved by an external force.
