Look at the third one i think its the answer
Answer:
Explanation:
Given
angular velocity 
Combined moment of inertia of stool,student and bricks 
Now student pull off his hands so as to increase its speed to suppose 
rev/s
After Pulling off hands so final moment of inertia is
Conserving angular momentum as no external torque is applied
I believe the correct answer from the choices listed above is option C. The instrument that is <span>best suited for measuring the dimensions of a shoebox would be a ruler. A triple-beam balance is for measuring mass. A volumetric flask is for volume. A caliper is measuring lengths of small objects.</span>
Given values:
Mass of the steel ball, m = 100 g = 0.1 kg
Height of the steel ball, h1 = 1.8 m
Rebound height, h2 = 1.25 m
a. PE= mgh
0.1 x 9.8 x 1.8 =
1.764 Joules
b. KE = PE ->
1.764 Joules
c. KE= 1/2 mv square
so v = square root 2ke/m
square root 2 x 1.764/ 0.1
= 5.93 m/s
d. KE=PE=mgh square
0.1 x 9.8 x 1.21 =
1.186 joules
velocity of rebond is square root 2x 1.186/ 0.1 = 4.87 m/s
