• What’s the difference between inertia and momentum?
  Inertia is the tendency of things to stay still unless they are ...

• What did a great scientist learn from an apple?
  The mathematician and physicist Sir Isaac Newton is said to have ...

• How is force measured?
  Force is measured in newtons, in honor of Sir Isaac Newton. A newton ...

• What is friction?
  Friction is the force between two things rubbing together, which may ...

• How fast does a stone fall?
  At first, the stone falls faster and faster at a rate of 9.8 metres ...

• Why can you jump higher on the Moon?
  The Moon is much smaller than the Earth, so its gravity is much ...

• Does gravity vary?
  An object's gravitational pull varies with its mass and its distance. ...

• Why do satellites go round the Earth?
  Satellites are whizzing through space at exactly the right height for ...

• How is natural oil made?
  Oil is formed from tiny plants and animals that lived in warm seas ...

• How do X-rays see through you?
  X-rays are stopped only by the bones and especially dense bits of the ...