Question

A barbell consists of two small balls, each with mass 500 grams (0.5 kg), at the ends of a very low mass rod of length d= 20 cm (0.2 m). The center of the barbell is mounted on the end of a low mass rigid rod of length b= 0.3 m (see Figure). The apparatus is started in such a way that although the rod rotates clockwise with angular speed 80 rad/s, the barbell maintains its vertical orientation.

Your answer is partially correct. Try again A barbell consists of two small balls, each with mass 500 grams (0.5 kg), at the ends of a very low mass rod of length d 20 cm (0.2 m). The center of the barbell is mounted on the end of a low mass rigid rod of length b 0.3 m (see Figure). The apparatus is started in such a way that although the rod rotates dlockwise with angular speed 80 rad/s, the barbell maintains its vertical orientation (a) Calculate L rot (both magnitude and direction). magnitude 110.8 kg m2ys direction nto page (b) Calculate L trams,B (both magnitude and direction) magnitude kg m2/s direction (c) Calculate (both magnitude and direction). magnitude kg m2/s direction ero magnitude; no dire

Answer 1

a)

Rotational angular momentum is

L_rot =rpsin90=0

since it does not rotate

b)

Zero Magnitude and no direction

c)

translational angular momentum

L_trans =IW=(2mb²)W=(2*0.5*0.3²)(80)

L_trans=7.2 Kg-m²/s

d)

into the page

e)

total angular momentum is

L_tot=L_trans =7.2 Kg-m²/s

f)

into the page