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Suppose you are applying some force on an object by your one of your hand let us say the force be $F_1$ .
Now you are applying another force on the same object by using both of your hands let us say the force be $F_2$ then the relation between $F_1$ and $F_2$ must be $$F_1<F_2$$ so,

Why we are not able to throw further with $2$ hands than with $1$ hand?

enter image description here

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    $\begingroup$ It depends what you are throwing. Have you seen an athlete throw a hammer? $\endgroup$ – Farcher Feb 27 '17 at 16:50
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    $\begingroup$ Has anyone actually tested that ? It would be instructive to measure how far, on average, you could throw a basketball as illustrated with one arm as you would with two. Perhaps an interesting high school experiment. $\endgroup$ – StephenG Feb 27 '17 at 17:35
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To throw far, one must throw at high velocity. The mechanics of the human body allow for the fastest velocities through the generation of high torque, rather than linear force. In other words, the high velocities are achieved by pivoting the body around an anchor point to generate rotational acceleration. This allows one to more effectively utilize one's entire body strength, including the elasticity of various ligaments, as is evidenced in the fastest baseball pitches. Clearly, such rotational motion can be best achieved when launching the object from one hand, rather than both simultaneously.

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  • $\begingroup$ +1 Got to hand it to you. (sorry)......best answer, better than mine anyway) $\endgroup$ – user146020 Feb 27 '17 at 16:41
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To throw an object a certain distance, you need to provide that object with momentum. Momentum is the integral of force over time.

If you look at how you throw with one hand, typically it involves a rotation of the shoulder, and maybe even part of the body. This means that the force can be applied over a greater distance, thus for a longer time.

By contrast, if you use both arms, the range of motion is typically much shorter. So while you have more force, the distance is less.

Often, the limit on the velocity you can reach is not given by the force of the muscle, but rather by the speed with which your muscles can contract. There again, if you are able to add rotation of the upper body, that results in speed of the shoulder which can then be added to the speed of the hand relative to the shoulder to give higher total speed.

Much of this is more about biology than about physics; but I hope the above gives you some insights into the complexity of this issue.

Some of this is nicely explained in this article, from which the following diagram gives you a sense of what I was talking about:

enter image description here

So if you have a very heavy object, it is possible that the additional force of two arms is significant (think of an object you cannot lift with one hand as an example); but for typical balls, other factors dominate.

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  • $\begingroup$ I said same thing in the figure in my answer only in a different way dont know why i am getting downvotes for it $\endgroup$ – ATHARVA Feb 27 '17 at 16:33
  • $\begingroup$ @ATHARVA - who knows why you get downvotes... Somebody didn't like your answer... that doesn't mean it was wrong. Stick around and you will find that "on average the system works", but there are always times when you go "what?". And a downvote without a comment explaining what is wrong with your answer is not very helpful, especially to a newcomer. $\endgroup$ – Floris Feb 27 '17 at 16:37
  • $\begingroup$ @ATHARVA you aren't saying the same thing. You never mentioned the release velocity, while that is essentially his whole point. Even your work analogy isn't that good. You could use two arms and swing half the distance to get the same output, which still seems feasible. You didn't really explain why that can't happen. This answer is comprehensive and explains where the limitation comes from. $\endgroup$ – JMac Feb 27 '17 at 16:40
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The force applied by two hands is greater but when we throw by two hands (the basketball) time or rather distance till the force applied is less. While when using one hand you can take your hand from back and start appling force for more time . Hence the work done while throwing by a single hand is more hence the ball goes far.(In greater sense you take the ball from your head or chest till both arms get stretch but while doing it single handedly you can apply force and take the ball from behind your head and you can also twist your body and hence apply the force for more time)

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  • $\begingroup$ There are two unjustified downvotes from nasty people. $\endgroup$ – Yashas Feb 27 '17 at 16:42
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    $\begingroup$ @Countto10 not for reputations I wanted to figure out what was wrong in the answer so that probably i may get corrected? $\endgroup$ – ATHARVA Feb 27 '17 at 16:43
  • $\begingroup$ But with two hands you have theoretically twice the applied force. Assuming they can travel half the distance you travel with 1 hand (I don't see why not) then they can apply the same work. $\endgroup$ – JMac Feb 27 '17 at 16:48
  • $\begingroup$ @JMac Force applied by hand also increases with time. Hence as time for contact is greater for two hands.Hence more work is done here. $\endgroup$ – ATHARVA Feb 27 '17 at 16:52
  • $\begingroup$ You cannot apply a force suddenly it increases with time. $\endgroup$ – ATHARVA Feb 27 '17 at 16:53
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While you are certainly right in stating that you apply more force when you use two hands, you haven't considered the fact that some component of your horizontal force of the two hands cancel out.

$$\vec{F} = m\vec{a} = \vec{F_1} - \vec{F_2}$$

enter image description here

Some part of the horizontal component of the forces cancel out.Here is a better diagram to compare the two.

enter image description here

Moreover, as kleingordon stated, it is difficult to apply a strong force in the direction of motion of the ball while using two hands. Combining these factors, using two hands is less efficient.

This is just a reasoning. In reality, it depends on the angle between the two hands and the capability of the person. Therefore, there is no definitive answer to the question: "Why we are not able to throw far by 2 hands than that by 1 hand?"

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protected by Qmechanic Feb 27 '17 at 19:09

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