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Solve (x^2 - 4)/(2x+4)

The common mistake the students make is to simplify the fraction before factorising numerator and denominator. Here, we need to see that the numerator: x^2 - 4 is a difference between squares , i.e. A^2 - B^...
MM
Answered by Martina M. • Maths tutor
4544 Views

A student of mass m=50kg runs an experiment. He throws a ball of mass m = 400g from a height h = 20m. What will be the speed of the ball he records just before it touches the ground?

First, we need to see what the important information in this problem is: the mass of the student is irrelevant as the problem focusses on the ball. So we now know that the important information is: m = 400g ...
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Answered by Martina M. • Physics tutor
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“Mao's ideology was the primary cause for the failure of the Great Leap Forward of 1958 to 1962.” Assess the validity of this view.

Getting started: This question is asking us to assess the validity of a particular view which means that we need to relate the interpretation to the evidence that we have, and assess how valid/accurate this ...
JF
Answered by Jacob F. • History tutor
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You are given a clear solution that is either an alkene or an alkane. Describe a test using bromine water that you could use to determine whether it is an alkene or alkane solution.

1 mark : Indication that the solution and bromine water should be mixed together1 mark : Indicating that the bromine water will de-colourise / go colourless if the solution contains an alkeneOR 1 mark awarde...
NH
Answered by Noah H. • Chemistry tutor
2795 Views

Part a) Draw the mechanism of the attack of CN- on CH3COCH3 in the presence of HCN Part b) Explain why the product of this reaction does not rotate the plane of plane polarised light

Part a) 1 mark : Show the nucleophilic attack of CN- at the carbonyl forming the O-1 mark : Show the protonation of the O- via the deprotonation of HCNPart b)1 mark: Student has identified that the intermedi...
NH
Answered by Noah H. • Chemistry tutor
4055 Views