Search our library of homework questions

Top answers

All subjects

All levels

How can I improve my "chain of reasoning" when explaining answers so I can achieve full marks for analysis (KAA)?

Producing a "chain of reasoning" in your answers is one of the more difficult requirements of the A level Economics syllabus. It is important when explaining your answers that you make clear and...

Answered by Tom W. • Economics tutor

6402 Views

Define relative formula mass (Mr) and calculate the relative formula mass of CaCO3. (Ar: Calcium= 40; Oxygen= 16; Carbon= 12)

The relative formula mass (Mr) of a compound is the sum of the relative atomic masses of the atoms in the numbers shown in the formula.

Relative formula mass (Mr) of CaCO3 = 40+12+(3x16)=100.

Answered by Charlotte M. • Chemistry tutor

79426 Views

How does the body regulate heat?

Body temperature is regulated by a thermoregulatory centre in the brain, the hypothalamus. The hypothalamus can sense the temperature of the blood via receptors. The skin also contains temperature recepto...

Answered by Natasha C. • Biology tutor

2484 Views

Solve 4x^2 - 3x - 4 = 0

There are two different methods of solving this equation and it is important to find the method that you find easiest.

The first method is to split up the numbers and the letters on both sides of t...

Answered by Oliver H. • Maths tutor

4724 Views

The circle c has equation x^2+y^2 = 1 . The line l has gradient 3 and intercepts the y axis at the point (0, 1). c and l intersect at two points. Find the co-ordinates of these points.

When approaching intersection problems, it is important to have both equations and solve them by substituting one into the other or simultaneously. First we need to find the equation of the line l since w...

Answered by Ellen T. • Maths tutor

3629 Views