HOW LONG COULD YOU SURVIVE ON BEER ALONE?
Beer typically has around 40 calories per 100ml (one pint = 568ml). To get your daily 2,000 calories just from beer, you’d need to drink 11 pints every day, which is hardly healthy. But the alcohol is the least of your problems. Beer, even real ale or Guinness, contains no fat, almost no protein and – crucially – no vitamin C. Without any source of vitamin C, you’ll experience symptoms of scurvy in two or three months and be dead in six.
WHY DO ROCKETS FOLLOW A PARABOLA AFTER LAUNCH?
Students have long been taught that all projectiles follow a curved path known as a parabola. The explanation is that, as they fly, they cover distance both horizontally and vertically – but only the latter is affected by the force of gravity, which bends the path of the projectile into a parabola. For longrange rockets, things are more complex. For example, air resistance must be taken into account. But, even ignoring that, a projectile doesn’t really follow a parabola – because the Earth isn’t flat. This means that gravity doesn’t simply pull objects straight back down. Instead, it pulls them towards the centre of the Earth, whose direction changes as the projectile moves further down-range, away from the launch site. Detailed calculations then reveal that the true trajectory is not a parabola, but part of an ellipse.