A packet is dropped from the window

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Homework Help Overview

The discussion revolves around the motion of a packet dropped from a helicopter moving upward. Participants explore the initial velocity of the packet and the effects of forces acting on it after being released.

Discussion Character

  • Exploratory, Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants question the initial upward motion of the packet and its velocity compared to the helicopter. They discuss the implications of Newton's laws and the effects of external forces like gravity and air resistance on the packet's motion.

Discussion Status

The discussion is active, with various interpretations being explored regarding the motion of the packet. Some participants provide insights into the physics involved, while others express confusion about the initial behavior of the packet after being dropped.

Contextual Notes

There is a noted lack of consensus on why the packet appears to move upward initially, with some participants emphasizing the role of the helicopter's upward velocity and others questioning this assumption.

Aladin
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A helicopter is moving with some velocity in upward direction,a packet is dropped from the window of the helicopter.why the packet goes upward after dropping?What will be the velocity of the packet ?is its velocity is same as the helicopter?why,why?please explain.
 
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Initially, the packet moves with the same velocity as the helicopter. Why would you think otherwise?
 
When you drop an object from a stationary window, there is an instant during which your hand is no longer supporting it, but it has not yet started to fall. (In most real-world instances this moment is vanishingly brief but, in some cartoon situations it can last indeffinately, and largely deoends on how long it takes for the object to notice that it is unsupported.)

If you repeat the same process in a vehicle that is moving upwards, the object still has a tendency to remain "staionary" for an instant, but that means stationary relative to your hand, which means "moving upward" relative to the ground.
 
Same idea as dropping something inside a train (similar to something in another thread). Although it drops straight down relative to the train, it describes a parabolic path relative to the ground.
 
Oddly, the OP seems to think that, initially, the packet actually goes up.
 
DaveC426913 said:
Oddly, the OP seems to think that, initially, the packet actually goes up.
Not so odd, since the helicopter is moving upward.
 
Well,think of Newton's 1st law. The packet already has a velocity and will continue in that constant velocity. There will however, be external forces, air resistance and gravity which will pull it downwards. The reason the helicopter does not fall as well is that there is a force upwards exerted by the helicopter blades, well, making it able to fly in the first place.
 
I am not understand please give me the reason that why the packet goes upward first.on the other hand the blades of helicopter are pushing air downward direction.then why the packet goes upward?
 
Last edited:
True. But the air from the blades that pushes the packet down is a force. It CHANGES the velocity, not set the initial velocity. The initial velocity is set by the helicopter's velocity. In other words, it will keep on moving at that velocity since it is already moving upwards in the first place. Of course it will slow down and later fall but that is because of the existence of forces.
 

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