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Why is Pluto not a planet any more?

When astronomers discovered Pluto in 1930, they were excited to announce it as the 9th planet in the solar system. The problem is, back then we didn't know that Pluto is just one of many objects floating in ...
RM
Answered by Ryan M. • Science tutor
6272 Views

Where does the quadratic equation come from?

This is a quick derivation of the quadratic formula for an GCSE Maths students looking to stretch themselves a little and go for that A*! If we have a general quadratic equation: ax 2 +bx+c=0 (eq1) You will ...
RM
Answered by Ryan M. • Maths tutor
5546 Views

Why there are multiple pronounciations for one single character in Japanese?

In Japanese writing and reading system there are two different ways to read Chinese Kanji characters: 訓読み ( kun yomi ) and 音読み ( on yomi ). Historically kun yomi is used as a way to mark the vernacular words...
XW
Answered by Xing W. • Japanese tutor
2929 Views

Two cars are crash tested. Car A has a crumple zone, B doesn't. Both cars have mass 1500kg and a driver of mass 80kg and crash at 20m/s. Cars A and B take 0.8 and 0.2 seconds to stop respectively. Using this information, are crumple zones a necessity? (6)

We need to show that car A is safer than car B and this is done by showing that the force is greater on car B than car A. Start by finding the force on car A, total mass 1580kg: Force is the change of moment...
JF
Answered by Jake F. • Physics tutor
13720 Views

Mark has a voucher that gives him 22% off the prices at a hardware store. Estimate how much he will pay for an electric drill that normally costs £87.99. (non-calculator) (3)

It is important to remember this is an estimate, so we can simplify the numbers by saying they get 20% off and the drill costs £90. (1) 10% off would be £9, so 20% off is £18. (1) They have 20% off so they p...
JF
Answered by Jake F. • Maths tutor
4626 Views