Throwing a ball horizontally on the moon and pushing it in the spacestation

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SUMMARY

The discussion centers on the differences in force required to throw a ball horizontally on the Moon compared to pushing it in the International Space Station (ISS). While the mass and inertia of the ball remain constant, the presence of atmospheric drag in the ISS necessitates a greater force to achieve the same horizontal motion as on the Moon, where negligible atmospheric resistance exists. Newton's second law (F=ma) is pivotal in understanding that the same force will produce the same acceleration in both environments, provided friction and air pressure are absent.

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Why is there a difference in force required throwing a ball horizontally on the moon and pushing it horizontally it in the spacestation
Thanks
 
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The mass and inertia of the ball is the same at both locations so no force difference there; however, there is an atmosphere maintained in the space station and therefore an aerodynamic drag resistance, whereas there is very little atmosphere on he moon so there is essentially no aerodynamic drag resistance there.
 
Martyn Arthur said:
Why is there a difference in force required throwing a ball horizontally on the moon and pushing it horizontally it in the spacestation
Thanks
The first question would be: What difference are you referring to?
 
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Thank you; I will try to be more clear, taking gravity away from all.
On the moon the astronaut requires the same force to throw the ball horizontally in the space station as the astronaut would on Earth.
On the space station would it require the same force to move a ball one meter, as it would to move the same ball horizontally one meter on Earth/ the Moon in the absence of friction and air pressure?

Thanks for your patience!
Martyn Arthur
 
Martyn Arthur said:
On the space station would it require the same force to move a ball one meter, as it would to move the same ball horizontally one meter on Earth/ the Moon in the absence of friction and air pressure?
Force doesn't move things, it changes their speed. The relevant equation is Newton's second law ##F=ma##; ##m## is the same in both cases so the same force will change the speed (##a## is the acceleration and that's just another word for "change of speed") by the same amount. And once you've started it moving, in the absence of friction and air resistance it will keep moving, so no matter how small a force you apply for how short of a time if you wait long enough it will have moved one meter.
 
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Could it be that the OP is talking about launching the same object so that it travels parallel with the surface of the Moon / Earth? It strikes me that the object would already be traveling horizontally in the space station if it's in a circular orbit so no force would be needed. If it's on the Moon's surface then you would need to accelerate it until it is in, effectively, a circular orbit at zero height above the surface. The Force needed would depend on how long or over what distance it acted so more information would be needed.
 
Martyn Arthur said:
Thank you; I will try to be more clear, taking gravity away from all.
On the moon the astronaut requires the same force to throw the ball horizontally in the space station as the astronaut would on Earth.
Any amount of force in the horizontal direction will "throw the ball horizontally". So this is a misleading statement.
On the space station would it require the same force to move a ball one meter, as it would to move the same ball horizontally one meter on Earth/ the Moon in the absence of friction and air pressure?
Any amount of force would start a ball moving in the horizontal direction. How far it will move is just a matter of how long you let it move. So this question can not be answered.
 
Only thing I see is if you are trying to get the ball to go 1 m before it hits the ground, you need to consider where it hits the ground. The horizontal force required to get the ball of fixed mass up to fixed horizontal velocity is essentially constant (ignoring air resistance), but the vertical acceleration is set by gravity. For a frictionless, elastic ball, the horizontal velocity doesn't change on impact with the ground (assuming a flat surface), so (it seems to me), the force required in all cases is constant if you care only about how fast the ball goes horizontally. If the ball needs to get over a mark on the ground 1m away, the required force (terminal horizontal velocity) on the ball increases with gravity.
 

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