# Recent content by Leong

1. ### Why does a log float horizontally?

Original question from the book: Logs dropped upright into a pond do not remain upright, but float ‘flat’ in the water. Explain. A long log can float vertically but this position of equilibrium is unstable. So, a slight tilt will make it tilt further from the vertical position until it reaches...
2. ### I Sin x < x

:ok::thumbup:
3. ### I Sin x < x

Thank you very much for the explanation.
4. ### I Sin x < x

Given that 0 < sin x < x is true for 0 < x < π/2. From the above, can we conclude that 0 < sin (x/2) < x/2? How about 0 < sin (x/5) < x/5? Why? How about 0<sin 3x < 3x ? Why?
5. ### Photoelectric effect

Would you mind explaining how the electrons flow in the circuit & how the current flows in the circuit?
6. ### Photoelectric effect

When the emitter is connected to the positive polarity of a battery, it is said that 'Some high speed electrons are still able to reach the collector and therefore there is flow of current.' (1) What is the flow of electrons like in this case? I thought electrons are supposed to flow from...
7. ### Tension in a spring

I think if you draw a free body diagram for a coil in the middle and another one for the coil near the wall, you may find that the sum of the tensions (the pulling force that acts on the coil) for the coil near the wall is greater than the sum of tensions that pulls the coil in the middle...
8. ### Normal force by a spring

Thanks for the explanation which I cannot find anywhere. Thanks to everyone who replied to my post.
9. ### Normal force by a spring

Do you mean spring force or normal force or both as the force on the book exerted by the spring on the book?[/COLOR]
10. ### Normal force by a spring

If there is no platform, just the book on the spring, will there still be a normal force on the book other than spring force and the weight of the book?
11. ### Normal force by a spring

Perpendicular
12. ### Normal force by a spring

Homework Statement A vertical spring is fixed on a table. A book is put on the spring. The book compresses the spring until static equilibrium is reached. Question: Is there a normal force exerted by the spring on the book? Why or why not? Homework Equations The Attempt at a...
13. ### Electrical and gravitational forces of protons

When r approaches zero or when they are very close to one another, the gravitational force is as large as the electrical force. Both the forces approach infinity. or When r approaches infinity or when they are very far apart, the gravitational force and the electrical force approach zero. Make...
14. ### Problem regarding centre of mass and linear momentum.

You're good. You can see the different reference frames and introduce relative velocity.
15. ### Problem regarding centre of mass and linear momentum.

What you said is very true.