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Why is there no wave for atrial repolarisation in the electrocardiogram?

While atrial repolarisation exists, you actually can't see it in the ECG! I can draw you a diagram of a normal cardiac cycle: this is the P wave, that you'll know represents the DEpolarisation of the atria. ...
SM
7172 Views

What is more important, quoting philosophers or having my own opinions

IB philosophy is set out for you to become the philosopher. It is more important to have you own opinion on each topic, using philosophers ideas to back up your opinion rather than quoting them. It is less i...
TF
2555 Views

When should you use the passé simple instead of the imparfait?

The "passé simple" is most often used in literary and formal writing express a completed past action. E.g. Un jour, elle tomba malade. (one day, she fell ill) The "imparfait" on the other...
AV
Answered by Annabel V. • French tutor
3255 Views

A student cut a piece of potato into 10 discs, each 1mm thick and with a 10mm diameter. He then placed them in a beaker of deionised water. After a couple of days, they had increased in size- both thickness and diameter. Explain why this is the case.

The cells composing the potato tissue contain fluid, or cytoplasm. This contains dissolved salts and these ions attract water molecules; cations, or positive ions, attract the partially negatively charged ox...
EK
Answered by Eva K. • Biology tutor
3509 Views

Solve the simultaneous equations: y-2x-4 = 0 (1) , 4x^2 +y^2 + 20x = 0 (2)

Re-arrange (1) : y = 2x + 4 Square both sides: y^2 = 4x^2 + 16 Substitute (1) into (2) and simplify: 2x^2 + 9x + 4 = 0 Factorise the equation: (2x+1)(x+4) = 0 Solve for x: x = -1/2 and x = -4 Substitute thes...
GA
Answered by Giorgos A. • Maths tutor
10113 Views