Answer: 71.7 KJ
Explanation:
The rotational kinetic energy of a rotating body can be written as follows:
Krot = ½ I ω2
Now, any point on the rim of the flywheel, is acted by a centripetal force, according to Newton’s 2nd Law, as follows:
Fc = m. ac
It can be showed that the centripetal acceleration, is related with the angular velocity and the radius, as follows:
ac = ω2 r
We know that this acceleration has a limit value, so , we can take this limit to obtain a maximum value for the angular velocity also.
As the flywheel is a solid disk, the rotational inertia I is just ½ m r2.
Replacing in the expression for the Krot, we have:
Krot= ½ (1/2 mr2.ac/r) = ¼ mr ac = ¼ 67.0 Kg. 1.22 m . 3,510 m/s2 = 71. 7 KJ
The earth rotates (spins) at the same time as it orbits in a circular motion around the sun. fun fact : it takes 365 days to complete 1 orbit for 3 years and then 366 days for a leap year! you don't have to put that last part but maybe for some extra points you can!
P.E = m*g*d
where m is the mass of body , d the vertical distance & g is the gravity acceleration and it equals constant = 9.81 m/s^2
so ,, P.E = 2 * 3 * 9.81
P.E = 58.86 N.m
Graduated cylinders have numbers on the side that help you measure volume