Projectile motion - time taken to hit the ground

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SUMMARY

The time it takes for an object to hit the ground is independent of whether it is dropped or thrown horizontally, due to the principles of projectile motion. When thrown straight down, the object falls faster than if simply dropped. The vertical and horizontal motions are independent, and the time to fall is determined solely by the height from which it is released, governed by the equation t = √(2h/g), where t is time, h is height, and g is the acceleration due to gravity. This relationship is rooted in the law of conservation of energy, where kinetic energy is converted to potential energy and vice versa during the object's descent.

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  • Understanding of basic physics concepts, particularly projectile motion
  • Familiarity with the law of conservation of energy
  • Knowledge of gravitational acceleration (g = 9.81 m/s²)
  • Ability to manipulate and understand mathematical equations, specifically t = √(2h/g)
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Can someone please explain to me why the time it takes for an object to drop down is the same time it takes to hit the ground if you throw it?

Thanks
 
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It depends how you throw it. If you throw it straight down, obviously it will fall faster in that case than it will if you just drop it. However, if you drop it horizontally, then it will take the same amount of time. This is because you can think of the object as moving in two directions, horizontally and vertically. In terms of the horizontal, you can tell what will happen. If you drop it, it doesn't travel horizontally. But, if you look at the vertical motion, there is no difference at all. Initially, it started with the same velocity going downwards (0) and it has the same acceleration (g). So they must fall down in the same amount of time. Vertical and Horizontal motion are completely independent.
 
for your question! The reason for this is because of the law of conservation of energy. When an object is thrown, it has a certain amount of kinetic energy that is gradually converted into potential energy as it rises and falls. At the moment of release, the object has a certain velocity, and as it falls, the velocity increases due to the acceleration of gravity. However, as the object falls, it also loses potential energy and gains kinetic energy. This exchange continues until the object reaches the ground, where all of its potential energy is converted back into kinetic energy and it reaches its maximum velocity. Since the acceleration due to gravity is constant, the time it takes for the object to reach the ground is the same as the time it takes for the object to fall from its initial release point. This can be represented by the equation t = √(2h/g), where t is the time, h is the height, and g is the acceleration due to gravity. I hope this helps to clarify the concept of projectile motion and the time it takes for an object to hit the ground.
 

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