# Frictionless body on Earth's Surface

• DBirk
In summary: If you left it stationary on the water, it would slowly drift due to the Coriolis effect (assuming you are not moving the Earth itself). However, if you moved the boat then the Coriolis force would act to keep it moving in the same direction.
DBirk

## Homework Statement

Will a frictionless body placed on the Earth move, and if so, describe it's path and acceleration.

## Homework Equations

I was given no equations, but I believe that coriolis and centripetal forces would act on the body.

## The Attempt at a Solution

I assume that we have to assume an initial velocity of 0 relative to the earth. However, from an external reference frame, the body would appear to be moving as a point on the earth. At the equator this would be approx 1040 mph. However, at latitude angle φ this would decrease as you move towards a pole to cosφ.
The coriolis acceleration, centripetal acceleration, gravity and a force normal to the Earth's surface would act on the body. I assume that gravity and the force normal to the Surface would cancel each other out, but I am not certain. I am having trouble identifying an equation that would capture all of these forces on the body.

You need to allow for the actual shape of tne Earth, i.e. not as a sphere.
Or just consider an object that exists on the Earth's surface and does behave pretty much as frictionless. Can you think of anything?

I can only think of fluids as such, water and atmosphere. Those have different behaviors though.
One man-made object that approaches frictionless would be a mag-lev train.
Similar question, would a mag-lev be (slowly) induced into movement by coriolis or other rotational Earth force if it was left stationary?

DBirk said:
I can only think of fluids as such, water and atmosphere. Those have different behaviors though.
One man-made object that approaches frictionless would be a mag-lev train.
Similar question, would a mag-lev be (slowly) induced into movement by coriolis or other rotational Earth force if it was left stationary?
I was thinking of a boat.

## What is a frictionless body?

A frictionless body is an idealized concept in physics that describes an object that experiences no resistance or friction when moving on a surface.

## Can a frictionless body exist in the real world?

No, a frictionless body is a theoretical concept used to simplify calculations and models in physics. In reality, all objects experience some form of friction when moving on a surface.

## How does the Earth's surface affect frictionless bodies?

The Earth's surface does not affect frictionless bodies as they are assumed to have no interaction with the surface they are moving on. In reality, the Earth's surface would create some form of friction that would affect the movement of an object.

## What is the significance of studying frictionless bodies?

Studying frictionless bodies allows us to understand the principles of motion and the effects of friction on objects. It also helps simplify calculations and models in physics, making it easier to study and analyze real-world situations.

## How can frictionless bodies be applied in real life?

Although frictionless bodies do not exist in the real world, the concept can be applied in designing machines and structures that aim to reduce friction and increase efficiency. For example, roller coasters and ball bearings are designed to minimize friction and allow for smooth movement.

• Introductory Physics Homework Help
Replies
17
Views
1K
• Introductory Physics Homework Help
Replies
6
Views
2K
• Introductory Physics Homework Help
Replies
2
Views
1K
• Introductory Physics Homework Help
Replies
23
Views
1K
• Introductory Physics Homework Help
Replies
5
Views
199
• Introductory Physics Homework Help
Replies
8
Views
328
• Introductory Physics Homework Help
Replies
9
Views
2K
• Introductory Physics Homework Help
Replies
6
Views
4K
• Introductory Physics Homework Help
Replies
1
Views
657
• Introductory Physics Homework Help
Replies
18
Views
2K