A motor-cyclist meets with an accident. During the collision the rider’s head strikes the road surface, but a well-padded helmet is worn.
a. (i) State the impulse–momentum theorem.
b. (ii) Explain, without using any equations, why a padded helmet reduces the likelihood of serious head injury when compared with riding without a helmet.
c. (iii) The magnitude of the impulse on the rider’s head is the same whether or not a helmet is worn. If the contact time without a helmet is about 2ms and the helmet increases this time to 6ms, by what factor does the average impact force change? Show your reasoning in one or two logical steps.