I'm stuck This is a combination of dynamics and free fall

In summary: The wind is pushing the cushion to the right, but the person is also exerting a force in the opposite direction. So there is an imbalance in forces and the cushion will curve to the right.
  • #1
devilish_wit
16
0

Homework Statement


A flat cushion of mass m is released from rest at the corner of the roof of a building, at height h. A wind blowing along the side of the building exerts a constant horizontal force of magnitude F on the cushion as it drops as shown in the figure below. The air exerts no vertical force.

image:
5-p-065.gif


If m = 1.03 kg, h = 7.85 m, F = 2.29 N, how far from the building (in m) will the cushion hit the level ground?

Homework Equations


F = ma

The Attempt at a Solution


I wasn't so sure about this question so..

I tried solving for the acceleration: F = ma ---> 2.29 = (1.03kg)(a) -----> a = 2.22 m/s^2
Then I solved for the time the object hit the ground in the y-direction: d = vit + at^2/2 ----> -7.85 = -9.8/2 t^2
-----> t = 2.22s
My solutions above might just be wrong. That's where I'm stuck right now.
 

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  • #2
devilish_wit said:
Then I solved for the time the object hit the ground in the y-direction: d = vit + at^2/2 ----> -7.85 = -9.8/2 t^2
You did not write out the equation before substituting numerical values.
How long will it be in free fall? You know; h = 1/2 ⋅ a ⋅ t2
t2 = 2 ⋅ h / a
t = Sqrt( 2 ⋅ h / a )
t = Sqrt( 2 * 7.85 / 9.8 )
t = 1.265 sec
 
  • #3
devilish_wit said:

Homework Statement


A flat cushion of mass m is released from rest at the corner of the roof of a building, at height h. A wind blowing along the side of the building exerts a constant horizontal force of magnitude F on the cushion as it drops as shown in the figure below. The air exerts no vertical force.
https://www.physicsforums.com/attachments/231892
A person stands on the roof of a building and releases a cushion from a height h above the ground. A rightward arrow indicates the wind force incident upon the cushion.
If the cushion is thrown downward with a nonzero speed at the top of the building, what will be the shape of its trajectory?

Answer: parabolic

Explain.

Homework Equations

The Attempt at a Solution



I can't exactly put it into words that make sense, but I just imagine that if you throw it at a certain speed downwards, the wind would push it towards the right, and make this parabolic shape. Can someone help me explain it in a clear way?[/B]
Think about the net force.
 
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1. How do dynamics affect my ability to get unstuck?

When you are stuck, dynamics play a crucial role in your ability to get unstuck. Dynamics is the branch of physics that studies the motion of objects and how forces affect that motion. In this situation, the forces acting on your body will determine whether or not you can get unstuck.

2. What is free fall and how does it relate to being stuck?

Free fall is when an object is falling under the influence of gravity alone, with no other forces acting on it. In the context of being stuck, free fall can occur when you are falling or slipping downwards, making it difficult to get unstuck.

3. How does friction play a role in getting unstuck?

Friction is the force that resists motion between two surfaces in contact. In the case of being stuck, friction can either help or hinder your ability to get unstuck. For example, if you are stuck on a slippery surface, the friction between your body and the surface may be reduced, making it harder to get a grip and get unstuck.

4. What other factors should I consider when trying to get unstuck?

Aside from dynamics and free fall, other factors that can affect your ability to get unstuck include your body's strength and flexibility, the type of surface you are stuck on, and the presence of any other objects or obstacles that may be blocking your way.

5. Is there a specific technique or method I can use to get unstuck?

There is no one-size-fits-all method for getting unstuck, as it depends on the specific situation and the individual's physical abilities. However, some general tips include staying calm, assessing your surroundings and available resources, and using your body's natural movements and leverage to try and get unstuck.

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