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A block of mass (m) is placed on a rough slope inclined at an angle (a) to the horizontal, find an expression in terms of (a) for the smallest coefficient of friction (x), such that the block does not fall down the slope.

The first thing to do as with any mechanics question is draw a force diagram with the weight (mg), the friction (F) and the normal reaction (R). As we are finding the smallest coefficient of friction poss...

Answered by Ollie W. • Physics tutor

4486 Views

By using the substitution x = tan(u), find the integral of [1 / (x^2+1) dx] between the limits 1 and 0

First we need to change the limits, and by plugging in 1 and 0 to our substitution we find that the limits for u are arctan(1) and arctan(0) (or pi/4 and 0). Then we need to substitute for dx, and by diff...

Answered by Ollie W. • Maths tutor

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Which element, Na or Mg is likely to have the higher melting point? Give reasons for your choice

Sodium and Magnesium are both metals, when they are solid they form a metallic lattice held together by the electrostatic force of attractive between the positive metal ions, and the negative delocalised ...

Answered by Monique P. • Chemistry tutor

21853 Views

How do I structure an successful essay based on comparing novels?

To structure a successful essay on comparing literary works, it is key to introduce an argument that compares the two set texts, and not talk about them seperately. To start the essay off, you should use ...

Answered by Megan G. • English Literature tutor

5286 Views

Explain the geometry and bond angles in a NH3 molecule

So if we think about a molecule of ammonia, NH3, there are 3 hydrogens, each with 1 electron (as its atomic number is 1) covalently bonded to 1 nitrogen atom with 5 outer shell electrons on it due to its ...

Answered by Anthony L. • Chemistry tutor

31253 Views