Question

Definitions and Equations: Moment of Inertia (D): Tendency to resist angular acceleration; the angular equivalent of mass. In practical terms it is a measure of how hard it is to rotate an object or segment, like a baseball bat or a body segment. It is the sum of the products of the mass (m) with the square of its distance from the axis of rotation (ka). SEE FINAL TWO PAGES OF THIS LAB EOR CHARTS NEEDED TO CALCULATE L. 1 mk2 . Linear Momentum (L.): • L-mv (kg*m/s) Moment of Inertia: 1. A 150 kg male football player that is 2.0 m tall is performing straight leg raises (hip flexion and extension while keeping the knee extended). What is his total moment of inertia for the leg about the hip (coxofemoral joint)? Segment Mass k k2 Total 1 2. Joey Votto (Cincinnati Reds 1st baseman) is performing lateral shoulder raises in the on deck circle before he bats in a game. He weighs 100 kg and has a height of 1.85 m. What is the moment of inertia for his arm, with the shoulder (glenohumeral joint) being the axis of rotation? Segment Mass k kz 1 Total 1 Momentum: 1. Determine the momentum for a 60 kg basketball player who is cutting across the court at 9 m/s. 2. Michael Phelps (mass -88.46 kg) dives off the diving block and swims 100 m (2 laps) in a time of 47.0 seconds. What is his momentum for the first 50 m (assume his velocity is constant over the entire race)? 2

Answer 1

m- Momentum (1) - Gokg; u=q mis momentum = mu = 60x9 =) 540 kgm/s m=1500kg u= 98.35 mis momentum = 15oo X98.35 - 147525 kgm/s (4) m=90kg u=lomis momentum = mu =90x10 900 Kanals m = 630 kg 42.5mlo momentum = mu = 630x42.5 - = 26775 kg mis