A rider in an equestrian event falls off her horse and strikes her head on the g

Question

A rider in an equestrian event falls off her horse and strikes her head on the ground. Luckily, she is wearing a helmet. At the first instant of impact the vertical velocity of the rider’s head is 5.8 m/s. The mass of the rider’s head is 5 kg. The helmet is lined with energy-absorbing material that is 3.0 cm thick. The thickness of the hard outer shell of the helmet, as well as the innermost padding used for fit and comfort, allows the head to displace 1.5 cm during the impact while crushing and compressing the energy-absorbing material and padding as well as the dirt that her head hits. What is the average force exerted by the helmet on the rider’s head during the impact from the fall?

Explanation / Answer

force = mass*acceleration

F=m*(vdv/ds)

where v is velocity and dv is change in velocity and ds is displacement

so here v is 5.8m/s

dv =5.8 - 0 =5.8(because final velocity is zero)

ds=1.5cm =0.015m

F=5*(5.8*5.8/0.015)= 11213.34N =11.213KN

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.