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What is diffusion and why is it important in both animals and plants?

Diffusion is a passive process involving the movement of molecules from a region of a higher concentration to one of a lower concentration (the term passive means that the process does not require an input o...
MC
Answered by Mathew C. • Biology tutor
186984 Views

What is an (electrostatically) induced charge?

When an electrically charged object (e.g rod) charges an uncharged object (e.g. metal sphere) that is nearby with the opposite charge. How does this happen? The charged rod causes the charges on the sphere t...
HT
Answered by Herminia T. • Physics tutor
23265 Views

How to analyse a source?

Analysing a source at first often feels like a daunting task, especially because it is unseen material, but it needn’t be! If you simply focus on what the question if asking you to do and structure it in an ...
ML
Answered by Matthew L. • History tutor
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Two electrons are a distance r apart, the first electron exerts a force F on the second electron. a) What force does the second electron exert on the first? b) In terms of r, at what distance is the force that the first electron exerts on the second F/9?

This question is on electric forces between charged particles. A useful equation to consider is Coulomb's law: F=k(Q 1 Q 2 )/R 2 Where k is the Coulomb's law constant:k~9.0x10 9 Nm 2 /C 2 Q is the charge on ...
RW
Answered by Ross W. • Physics tutor
7150 Views

A rollercoaster carriage of mass 100kg has 45kJ of Kinetic Energy at the lowest point of its ride. Ignoring air resistance and friction between the wheels and the tracks, what is the maximum height above this point it could reach? [Take g as 10m/s/s)

[A useful tip: always start by drawing a diagram!!]This question is asking you to apply conservation of energy, i.e. at the highest point it can reach above the lowest point, all of this Kinetic Energy will ...
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Answered by Ross W. • Physics tutor
4565 Views