angular velocity- need help!

hiphop2009 SG

A majorette in the Rose Bowl Parade tosses a baton into the air with an initial angular velocity of 2.5 rev/s. If the baton undergoes a constant acceleration while airborne of 0.2 rev per second square, and its angular velocity is 0.8 rev/s when the majorette catches it, how many revolutions did it make in the air?

14 rev
1 rev
44 rev
4 rev

choose one.

darkhour SG

ur qn got problem anot?if its accelerating at 0.2rev per second square, how can the final velocity b lower than the intial velocity?

eagle SG

I think you mean deceleration of 0.2 rev/s

remember in linear mechanics

v^2 = u^2 + 2as

in angular mechanics, the formula to be used is analogous
ie

(final angular velocity)^2 = (initial angular velocity)^2 + 2 * (acceleration) * (revolutions)

so,

0.8^2 = 2.5^2 + 2 (-0.2) (rev)
resolving,
rev = 14 revolutions

hiphop2009 SG

ooooo. thanx!. hehe~