# The Earth's Rotational Speed: Where to Stand for Minimum Speed?

• hatingphysics
In summary: If the hands are close to each other, the distance between them is small, so the speed would be small. If they are far apart, the distance is large, so the speed would be large.
hatingphysics
1) The Earth rotates once per day about its axis. Where on the Earth's surface should you stand in order to have the smallest possible tangential speed?

would it be on the top of axis since it will not move?

2) It is possible, but not very practical, to build a clock in which the tips of the second hand, the minute hand, and the hour hand move with the same tangential speed. Explain why it would be possible but not practical.

I have no idea here...i didn't even know this was possible?!3) Suppose that the speedometer of a truck is set to read the linear speed of the truck, but uses a device that actually measure the angular speed of the tires. If larger diameter tires are mounted on the truck, will the reading of the speedometer be correct? if not, will the reading be greater than or less than the true linear speed of the truck? Why?

No, because the diameter is more for the wheel which will give a larger speed compared to the linear speed. Is this true...i don't know what the right answer is.

4) The blades of a fan rotate more and more slowly after the fan is shut off. Eventually they stop rotating altogether. In such a situation we sometimes assume that the angular acceleration of the blades is constant and apply the equations of rotational kinematics as an approximation. Explain why the angular acceleration can never really be constant in this kind of situation.

is it because the speed of the fan turning off is changing till it stops?

5) Rolling motion is one example that involves rotation about an axis that is not fixed. Give three other examples. In each case, identify the axis of rotation and explain why it is not fixed.

i have no clue!

Last edited:
One is expected to show one's own efforts before requesting help.

hatingphysics said:
2) It is possible, but not very practical, to build a clock in which the tips of the second hand, the minute hand, and the hour hand move with the same tangential speed. Explain why it would be possible but not practical.

I have no idea here...i didn't even know this was possible?!
Think of the length of each hand.

## 1. What is the Earth's rotational speed?

The Earth rotates at a speed of approximately 1670 kilometers per hour at the equator.

## 2. Does the Earth's rotational speed vary at different locations?

Yes, the Earth's rotational speed decreases as you move away from the equator towards the poles. This is due to the Earth's shape and its rotation around its axis.

## 3. Where is the minimum rotational speed on Earth?

The minimum rotational speed on Earth is at the poles, where the rotational speed is close to zero.

## 4. Is there a specific location on Earth where the speed is the minimum?

Yes, there is a specific location on Earth where the rotational speed is the minimum. This location is called the geographic South Pole, located at 90 degrees south latitude.

## 5. Why is it important to understand the Earth's rotational speed?

Understanding the Earth's rotational speed is important for various reasons, including calculating time zones, predicting weather patterns, and understanding the Earth's climate and environmental changes.

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