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If an object is falling freely under the action of gravity alone without any external resistance then the situation is called free fall.
During free fall an object falls with the acceleration which is equal to the acceleration due to gravity of that planet or satellite.
i.e. Acceleration of falling body = acceleration due to gravity during free fall. a = g
But if there is air resistance the situation of free fall does not arise. Thus, if there is no freefall then a < g
The paratroopers land safely on the ground with the help of parachute:
It is because no free fall takes place if a person is falling with the help of a parachute. The parachute will increase the air resistance. Due to this, the acceleration of the falling parachute becomes less than the value of acceleration due to gravity. As a result, he or she could safely land on the ground.
In case of the moon:
One cannot land safely, because due to the absence of the atmosphere (air resistance). Hence, the parachute will fall freely on the moon. There is a high chance of getting hurt.
The probability of getting hurt is more when one falls from the significant height because:
The ground striking velocity while falling from a significant height will be more and, therefore, the effect of force also will be more. It is because momentum (M) will be more since,
Momentum = Mass x Final Velocity
i.e. p = m x V
If the reaction that makes us conscious of our weight, when we stand or walk, becomes zero due to some reasons, one will feel weightless. Weightlessness is the condition in which the weight of the body seems to be zero. A body with a fixed mass will be weightless under the following conditions:
When there is no air resistance, a coin and a feather fall together. Acceleration of the feather and a coin at that instant is 9.8 m/s2. All objects fall towards the earth"s surface with the same acceleration despite the difference in masses if air resistance is not there. In reality, the objects with greater mass fall faster because they experience less air resistance. But, as the coin and feather do not experience any air resistance they have the same acceleration.
The free fall is defined as the falling of an object in absence of any external resistance with acceleration equal to the acceleration due to gravity.
Weightlessness is a condition when any object falls freely under the action of gravity experiencing no weight of its own.
On the earth the parachute at first falls with higher speed. But after certain time the upthrust of the earth and its downward force balance eachother. Due to balance forces it attains a constant velocity. But on the moon there is no atmosphere. Therefore, parachute falls down with acceleration due to gravity on the moon.
Air is always present in real life due to the obstruction of air objects do not fall freely.
Free fall does not takes place if a person is falling with the help of parachute, because it will ______.
increase the air resistance
decrease the air resistance
none of the answers are correct
not change the air resistance
The probability of getting hurt is more when one falls from the significant height because ______.
The ground striking velocity while falling from a significant height will be less and therefore the effect of force also will be more
The ground striking velocity while falling from a significant height will be less and therefore the effect of force also will be less
The ground striking velocity while falling from a significant height will be more and the effect of force also will be less
The ground striking velocity while falling from a significant height will be more and therefore the effect of force a will also be more
Why it is not safe to use parachute on the moon?