By lucas posso romo

The best tip for any revision is to start with the past exam papers and work back from that. Otherwise you will spend a lot of time revising the wrong stuff, or the right stuff in the wrong way.
All past papers and mark schemes are available for free for you to download. You need to know your exam board and specification, but you can start here:-
Edexcel -

Tabitha Farrant

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Tabitha Farrant
By trust mambemba

Sorry if this is too complex, but it give you the idea.
Pacemaker cells in the sinoatrial node, located over the right atrium, initiate the cardiac cycle. Systole begins when excitation spreads over both atria, activating atrial contraction. Excitation spreads to the atrioventricular node, near the atrioventricular border, from which excitation is conducted by the bundle of His and the Purkinje system (groups of specialized muscle cells) to the bottom of the ventricles. Excitation spreads upward in the ventricles, contracting them from the bottom up, like squeezing a toothpaste tube from the bottom. When the action potentials end, diastole (relaxation) begins, until excitation is again initiated by the pacemaker cells of the sinoatrial node.

Tabitha Farrant

what is its speed after 8sec?
how long will it take to reach a speed of 36ms?


v = u+a.t
U= initial velocity = 0
So v = a.t
a=4, t=8. Pop in the numbers and get the answer
Rearrange v=a.t to get
t =v/a
Velocity required = V = 36. a=4
Pop in the numbers and get the answer
For distance you have to use s=ut + 0.5a.(t.t) (t.t) = t squared
initial velocity u=0 so ut = 0
Rearrange to get
t = ????
Pop the numbers in to get the answer
To get the speed after that time, use v = a.t again as per the start of the question
Finally to get distance (s) travelled in the 3rd second, find out the speed at the start (t=2) of that second using the techniques above. That will be u, initial velocity for this part of the question.
Then use s=ut + 0.5 a(t.t) to get the distance, s.

Tabitha Farrant

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By Razinah Maudarbux

How can anyone say we have "market failure" when we don't have real "markets". The real sin of the so called Capitalists is market development or lack there of. Globalization was a great idea but done incorrectly. American business took jobs from Americans who made enough money to be great consumers and gave them to foreign workers who they paid so poorly they could not take the place of the lost American markets ( American workers).
The true capitalist would have invested in growth to the new markets. What I mean is that they would have kept the American market (American manufacturing plants and offices with the well paid workers) but opened factories and offices in other countries paying the workers a fair wage so that those workers could buy the products they made. This is true capitalism. this type of capitalism takes into account both supply and demand.
Supply side economics is what has gotten us into this near depression and is what is keeping America from getting out of this slump. Consumerism will not reappear until well paying jobs are redeveloped. Without consumers all the goods those low paid workers make will sit in your warehouses. Without demand your supplies are worthless.
For the virtuous investment cycle to work, there has to be a healthy environment for entrepreneurs and inventors. These are usually not among the wealthy when they get started. It is a historical fact that when wealth is concentrated in the hands of the few, rather than seeking new opportunities for wealth creation they often manipulate the rules and regulations to protect what they have. This results in an environment that is unhealthy for entrepreneurial enterprise and as middle classes shrink, is similarly unhealthy for the consumer markets that new small business relies on for their customer base. As a small but influential group of high wealth individuals in the US undercuts our education system, middle class labor rules, voter rights, access to health providers, etc., etc. etc., we get closer and closer to a banana republic situation of guarded palaces and wide spread poverty. Not quite what the founding fathers had in mind when they cast off the bindings of European aristocratic rule. Our so called conservative representatives are so greedy and addicted to campaign donations from the wildly misnamed "club for growth", that this basic truth eludes them.
P.S. These are my thoughts on the topic based on all the reports and researches I did with so they might be flawed but to me they aren't

Melanie Knights

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