The question is below; was too large

Question

Yuzuru Hanyu wants to become the first figure skater to land a quadruple axel (4.5 rotations). Nicknamed “The Projectile”, he figures that he must achieve a maximal height of 0.8m and have an angular momentum of -70kg·m^2/s for the clockwise jump. Assuming these values to be true, what moment of inertia must he generate to successfully complete the jump? Hint: you will need to use equations of linear motion to solve the problem.

Answer 1

Angular momentum is moment of inertia times angular velocity: L = I ω

L is given as 70. Using linear kinematics we can find that the time t in the air is 0.8 seconds, and the angle of rotation needed is 9π radians, so now we have ω = 9π / 0.8 = 11.25π

70 = I 11.25π

so

I = 70 / (11.25π) = 1.98 kg m^2/s^2