Understanding Inertia: Explaining the Door Closing Phenomenon in Moving Cars

[Einstein1729]

Explain the phenomenon of closing of door of a car when car starts accelerating forward please explain in ground frame.

 

[Nidum]

What forces do you think might be acting on the door ?

 

[Einstein1729]

What forces do you think might be acting on the door ?

In ground frame I think no force.But wrt to car frame there is one pseudo force.

 

[sophiecentaur]

In ground frame I think no force.

Wouldn't that mean the door would be left behind by the car?

 

[jim mcnamara]

The question is hard to answer in part because the title is no help, you need to use plain English, the question is not very clear.
Please take the time to read the rules about how to post.

Thanks.

 

[Einstein1729]

In ground frame I think no force.

Wouldn't that mean the door would be left behind by the car?

I know that's why I want to know how it closes? Wrt ground frame

 

[jbriggs444]

I know that's why I want to know how it closes? Wrt ground frame

Does the door have hinges?

 

[Einstein1729]

Does the door have hinges?

Yes

 

[Dale]

Explain the phenomenon of closing of door of a car when car starts accelerating forward please explain in ground frame.

In the ground frame the force at the hinge both accelerates and rotates the door. It is important to recognize that the hinge is not the axis of rotation since it is accelerating in this frame. Since it is not the axis of rotation, forces at the hinge can generate torque about the axis of rotation.

 

[Einstein1729]

In the ground frame the force at the hinge both accelerates and rotates the door. It is important to recognize that the hinge is not the axis of rotation since it is accelerating in this frame. Since it is not the axis of rotation, forces at the hinge can generate torque about the axis of rotation.

What is the axis of rotation in case of ground frame?and how is the force be able to rotate backward if the force at hinge is in forward? I am sorry if I am wrong.

 

[Dale]

What is the axis of rotation in case of ground frame?

You have to solve for it mathematically, it is not obvious.

how is the force be able to rotate backward if the force at hinge is in forward?

As long as the axis is anywhere outside the car, the forward force will rotate the door closed.

 

[CWatters]

how is the force be able to rotate backward if the force at hinge is in forward?

Does the centre of mass of the door move "backwards" relative to the ground?