Mr and Mrs Wallace hire a van for moving house. They see this advert in the local paper and decide to use this company. When they hand the van back, their bill comes to £59. How many hours did they ...

Melting and freezing are both physical changes, which are often easy to reverse. To reverse this process, the water would need to be cooled enough until it freezes back into ice. This works because ...

LaTeX or Word? For physicists and mathematicians, the choice is obvious. But for scientists in other fields the merits of LaTeX have largely gone unnoticed. The open-source software system — used to ...