Conceptual check: Newton's third law

In summary, the air particles inside a spherical rubber balloon exert an outward force on the rubber perpendicular to the surface, while the air outside the rubber exerts a lesser outward force perpendicular to the surface. The matching force for the inside air pushing out is the balloon rubber pushing against the air, and the matching force for the outside air pushing in is the inside face of the balloon pushing inward on the inside air.
  • #1
Callista
5
2

Homework Statement


A spherical rubber balloon inflated with air is held stationary, with its opening, on the west side, pinched shut. (a) Describe the forces exerted by the air inside and outside the balloon on sections of the rubber.

Homework Equations


?

The Attempt at a Solution


upload_2019-3-10_15-20-41.png

The air particles inside the balloon will push outwards on the rubber perpendicular to the surface. The air outside the rubber will push against the rubber perpendicular to the surface, and to a lesser degree. What I can't figure out is what WOULD be the matching force on each the air pushing in and the air pushing out.

Maybe the balloon rubber pushing against the air?
 

Attachments

  • upload_2019-3-10_15-20-41.png
    upload_2019-3-10_15-20-41.png
    51 KB · Views: 943
Physics news on Phys.org
  • #2
Callista said:

Homework Statement


A spherical rubber balloon inflated with air is held stationary, with its opening, on the west side, pinched shut. (a) Describe the forces exerted by the air inside and outside the balloon on sections of the rubber.

Homework Equations


?

The Attempt at a Solution


View attachment 240051
The air particles inside the balloon will push outwards on the rubber perpendicular to the surface. The air outside the rubber will push against the rubber perpendicular to the surface, and to a lesser degree. What I can't figure out is what WOULD be the matching force on each the air pushing in and the air pushing out.

Maybe the balloon rubber pushing against the air?
yes, if the air inside pushes outward on the inside face of the balloon, then the inside face of the balloon must push inward on the inside air. That is one force pair. But wait, there is another. What is it??
 

1. What is Newton's third law?

Newton's third law states that for every action, there is an equal and opposite reaction. This means that when an object exerts a force on another object, the second object will exert an equal and opposite force back on the first object.

2. How does Newton's third law relate to everyday life?

Newton's third law can be observed in everyday life in many ways. For example, when you push a door, the door pushes back on you with an equal force. Another example is when you jump, your feet push down on the ground and the ground pushes back, propelling you into the air.

3. Can you give an example of Newton's third law in action?

Yes, a common example is a rocket launching into space. The rocket exerts a force downward on the ground, and the ground exerts an equal and opposite force upward on the rocket. This allows the rocket to lift off and overcome the force of gravity.

4. How does Newton's third law apply to objects at rest?

Even when objects are at rest, Newton's third law still applies. This is because there are always forces acting on objects, even if they are not moving. For example, the force of gravity pulling down on an object is countered by the force of the surface supporting the object pushing up.

5. What is the importance of understanding Newton's third law?

Understanding Newton's third law is crucial in understanding the fundamental principles of motion and how forces interact with each other. It also helps in predicting and explaining the motion of objects, and is essential in fields such as engineering and physics.

Similar threads

Newton's Third Law for book on a table
    • Introductory Physics Homework Help
Replies
8
Views
2K
How do you identify the systems in which Newton's Third Law is obeyed?
    • Introductory Physics Homework Help
Replies
6
Views
774
Why doesn't Newtons third law also apply to the frame?
    • Introductory Physics Homework Help
Replies
2
Views
2K
Understanding Newton's Third Law in Action: A Truck Pushing an SUV
    • Introductory Physics Homework Help
Replies
4
Views
1K
Newton's third law problem/kinematics (Airboat problem/no friction)
    • Introductory Physics Homework Help
Replies
3
Views
3K
B Newton's third law (equal and opposite force)
    • Classical Physics
2
Replies
40
Views
2K
Newton's Third Law Confusion
    • Introductory Physics Homework Help
Replies
18
Views
2K
Force between charged Ring and Rod, disproved Newtons 3rd law?
    • Introductory Physics Homework Help
Replies
3
Views
861
Newton's third law: Rower makes boat move forward
    • Introductory Physics Homework Help
Replies
2
Views
5K
Newton's Third Law: Acceleration of box and worker
    • Introductory Physics Homework Help
Replies
2
Views
4K

Hot Threads

Recent Insights

Back
Top