Member of the e-learning unit in Newcastle University's School of Mathematics and Statistics.

Lead developer of Numbas.

I'm happy to answer any questions - email me.

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Christian Lawson-Perfect commented on Impulse transmitted through a string between two objects 9 years, 4 months ago

Tidied up the advice and made the title more descriptive.

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Christian Lawson-Perfect on Relate impulse to change in momentum 9 years, 4 months ago

Gave some feedback: Ready to use

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Christian Lawson-Perfect commented on Relate impulse to change in momentum 9 years, 4 months ago

Rejigged the squash problem so it's physically possible: the rebound speed must be at most the initial speed.

A coefficient of restitution is picked, then the impulse is calculated based on that, and rounded off to 1 d.p. 

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Christian Lawson-Perfect on Find change in speed after force applied for given time 9 years, 4 months ago

Gave some feedback: Ready to use

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Christian Lawson-Perfect commented on Find change in speed after force applied for given time 9 years, 4 months ago

Made the title more descriptive.

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Christian Lawson-Perfect on Calculate momentum given mass and speed 9 years, 4 months ago

Gave some feedback: Ready to use

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Christian Lawson-Perfect commented on Calculate momentum given mass and speed 9 years, 4 months ago

Made the title more descriptive.

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Christian Lawson-Perfect on Force acting on an object at an angle with friction 9 years, 4 months ago

Gave some feedback: Ready to use

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Christian Lawson-Perfect commented on Force acting on an object at an angle with friction 9 years, 4 months ago

Made the title more descriptive, and had a go at tidying the advice.

The calculations are pretty hard to follow - I'd rather work it out in algebra first, then sub in values once I've got an equation for $P$.

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Christian Lawson-Perfect on Maximum frictional force acting on a mass 9 years, 4 months ago

Gave some feedback: Ready to use