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A cup of boiling water (100 degrees C) (0.2kg) transfers 20 000J of heat to its surrounding in 1 hour. What temperature is the water in the kettle after 1 hour?

To answer this we need to use the equation Q = MC(T1-T2) We want to know what T2 is (ie the temperature after one hour). So rearrange the equation to get T2 = T1 - Q/MC No substitute the values given: T2 = 1...
CJ
Answered by Callum J. • Physics tutor
4322 Views

How should I properly use a semi-colon?

There are many different ways in which a semicolon can be used. The first, and the most common is to link two similar clauses together. For example, you could say, 'The lady had a cat. The cat was brown', bu...
FO
Answered by Fern O. • English tutor
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Factorise the quadratic equation: x^2 + 5x + 6 = 0 and hence find the two solutions to the equation.

Start by writing the equation out again: x 2 + 5x + 6 = 0 I do it by thinking which two numbers add together to = 5 and which same two numbers multiply to = 6. The answer to this is 2 and 3. So the next step...
CJ
Answered by Callum J. • Maths tutor
8501 Views

i) Simplify (2 * sqrt(7))^2 ii) Find the value of ((2 * sqrt(7))^2 + 8)/(3 + sqrt(7)) in the form m + n * sqrt(7) where n and m are integers.

i) (2 sqrt(7)) 2 = 2 2 sqrt(7) 2 = 4 * 7 = 28 (1 mark) ii) First of all substitute the answer from above. ((2 * sqrt(7)) 2 + 8) / (3 + sqrt(7)) = (28 + 8) / (3 + sqrt(7)) = 36 / (3 + sqrt(7)) Multiply by (3 ...
AB
Answered by Andrew B. • Maths tutor
8135 Views

Work out 64^2/3

64/4/4=4 4x4=16 n.b no square root function on my divice
TL
Answered by Thomas L. • Maths tutor
3918 Views