# physics

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An American football game has been canceled because of bad weather in Cleveland, and two retired players are sliding like children on a frictionless ice-covered parking lot. William 'Refrigerator' Perry, mass 162 kg, is gliding to the right at 7.73 m/s, and Doug Flutie, mass 81.0 kg, is gliding to the left at 10.5 m/s along the same line. When they meet, they grab each other and hang on.

(a) What is their velocity immediately thereafter?
(b) What fraction of their original kinetic energy is still mechanical energy after their collision?
(c) The athletes had so much fun that they repeat the collision with the same original velocities, this time moving along parallel lines 1.07 m apart. At closest approach they lock arms and start rotating about their common center of mass. Model the men as particles and their arms as a cord that does not stretch. Find the velocity of their center of mass.
(d) Find their angular speed.
(e) What fraction of their original kinetic energy is still mechanical energy after they link arms?

for part a do you have to use rotational kinetic energy or is it just translational? the numbers i keep getting are way off

• physics -

Part A is linear momentum conservation.

• physics -

i see what i was doing wrong now. i didn't take into account that they're going in opposite directions