Question

A merry-go-round full of kids initially has 5.33 kg-m^2 while maintaining an angular speed = 2.55 rad/s. Some kids move closer to the center of the merry-go-round increasing its speed to omega y = 3.00 rad/s What's the final inertia Ly? How do the final and initial kinetic energies compare: K_r > K_y K_d < k_1 or K_1 = K ? if they are different then where did the delta K go to or come from? A solid ball a Hoop and a disk all have the same mass and radius. They are all rolling without slipping with the same total energy when they start rolling up a ramp Without sipping. Which is correct for the amount of time required for each object to reach its final height ?

#3

Answer 1

3 ans :

step1:

the time taken by rolling body to reach the height

t=1/sin(theta){2h/g(1+B)}^1/2

step2:

the B value for

solid ball =2/5

disk=1/2

hoop =1

step3:

now use the step1&step2 we get each one

time taken for solid ball to reach height =>Tball={2h/g(1+B)}^1/2

={2/9.8(1+2/5)}^1/2

={0.2041*1.4}^1/2

=0.535 sec

time taken for hoop to reach height =>Thoop={2/9.8(1+1)}^1/2

=0.64 sec

time taken for disk to reach height =>Tdisk={2/9.8(1+1/2)}^1/2

=0.6 sec

step4:

basing on step3

we decided the correct option is 3