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A diver of mass 60kg stands on the end of a diving board (2m in length). Calculate the upward force exerted on the retaining spring which is 30cm from the start of the diving board.

Here we have a typical moments question. The start of the diving board is the pivot (draw a picture)To answer this question we need to know that sum of the clockwise moments must equal the sum of the anticlo...
SA
Answered by Sophie A. • Physics tutor
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A gold leaf electroscope with a zinc plate top is charged by briefly connecting it to the negative electrode of a high-voltage supply. Explain how the gold leaf will appear and how the leaf can be caused to drop again.

The gold leaf will diverge from the metal stem. This is because connecting the negative electrode to the zinc plate, causes an influx of electrons to flow into the electroscope. When the electrode is removed...
RN
Answered by Rebecca N. • Physics tutor
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Why does gravitational potential energy have a negative value?

A point in a gravitational field has an associated gravitational potential. It is defined as the work done required to bring a unit mass from a point an infinite distance to that point in the field. At an in...
JP
Answered by Joseph P. • Physics tutor
3985 Views

How did rutherford's gold leaf experiment prove the existence of the nucleus?

Firstly the gold foil was flattened so that it was one atom thick. The researchers knew that alpha particles were positively charged, and so would be repelled by other positive charges. At the atomic scale t...
LH
Answered by Lucas H. • Physics tutor
6672 Views

A block of mass m is released from rest on a surface inclined at 30⁰ to the horizontal with a coefficient of friction of 0.3. How long does it take for the block to slide 1 m?

Firstly, a free-body diagram of the problem should be drawn indicating the forces acting on the block (remember that the friction force is the product of the normal reaction on the block and the coefficient ...
RP
Answered by Richard P. • Physics tutor
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