Human powered helicopter

Try your hand at some physics problems based on gravity set by St John’s Physics tutor Professor Tony Weidberg

Q: Many proposals have been made for a human powered helicopter. Consider the case of such a machine with a rotor 10 metres in diameter. Could a human create enough power to overcome gravity? The density of air is 1.23 kg m-3.

Q: Make a reasoned approximate estimate of the height a “pole-vaulter” could succeed in obtaining.