Search our library of homework questions

Top answers

All subjects

All levels

Explain why hydrogen bonding occurs between water molecules

Water molecules have a molecular formula of H2O. The O-H bond in water is a polar bond. This is because there is a big difference in electronegativity between the oxygen and the water. It is known that ox...

Answered by Mohammed A. • Chemistry tutor

16656 Views

What is the difference between the independent and dependent variables.

The best way to remember the difference between independent and dependent variables is when you are conducting an experiment you are looking to see if one variable (the independent variable) has an effect...

Answered by Emily H. • Psychology tutor

8904 Views

A nail of mass 7.0g is held horizontally and is hit by a hammer of mass 0.25kg moving at 10ms^-1. The hammer remains in contact with the nail during and after the blow. (a) What is the velocity of the hammer and nail after contact?

The principle necessary to answer this question is the conservation of linear momentum. This means that the sum of the momentum of the hammer and nail before impact must be equal to the total momentum of ...

Answered by Caroline S. • Physics tutor

6762 Views

Solve x^2 + 15x = - 50

x² + 15 x + 50 = 0 (rearrange by adding 50 to both sides)
(x + 10)(x + 5) = 0 (factorise the quadratic equation)
x + 10 = 0 or x + 5 = 0 (for the a...

Answered by Julia S. • Maths tutor

8320 Views

Explain why it can be said that we live on a 'shrinking' planet?

The term 'shrinking' planet is another way of referring to the process of globalisation, or the deepening and strengthening of ties across transnational borders. This manifests itself in two main ways - g...

Answered by Paul F. • Geography tutor

3352 Views