Search our library of homework questions

Top answers

All subjects

All levels

Mechanics 1: How do you calculate the magnitude of impulse exerted on a particle during a collision of two particles, given their masses and velocities.

Conservation of momentum is the key principle always used in problems of these type. Here, it asks for the impulse, which is a force measured in Newtons, and it is defined as the change in momentum. F=m(v...

Answered by Ina H. • Maths tutor

25925 Views

A curve is described by the equation (x^2)+4xy+(y^2)+27=0. The tangent to the point P, which lies on the curve, is parallel to the x-axis. Given the x-co-ordinate of P is negative, find the co-ordinates of P.

Firstly, implicitly differentiate the function to find dy/dx in terms of y and x: dy=dx = (-x-2y)/(2x+y). Secondly, set this equal to zero to obtain an expression of y in relation to x or vice versa: x=-2...

Answered by Rahul P. • Maths tutor

7874 Views

How do you know whether to use a or à in a sentence?

If can replace a with 'avait' for instance they you do not need an a with apostrophe. i.e je vais à la cantine. (the sentence would not make sense if you were to replace à with avait hence you need 'à' an...

Answered by Dominique O. • French tutor

1802 Views

How do you engage with critics in an essay?

This is a key skill which confuses a lot of people and really marks out A* candidates. It needn’t be all that difficult and with eight techniques you can have it in the bag. Firstly, try to consider criti...

Answered by Skye O. • English tutor

11147 Views

What are the half equations representing the changes of Pb2+ and Br- in the electrolysis of lead bromide?

Pb2+ + 2e- -> Pb 2Br- -> Br2 + 2e- Lead ions undergo reduction (gain of electrons) at the negative electrode to form solid lead. Bromide ions undergo oxidation (loss of electrons) at the positive el...

Answered by Sophie F. • Chemistry tutor

36972 Views