Answer:
the answer to the question is 13
Answer:
See explanation
Explanation:
We have a mass
revolving around an axis with an angular speed
, the distance from the axis is
. We are given:
![\omega = 10 [rad/s]\\r=0.5 [m]\\m=13[Kg]](https://tex.z-dn.net/?f=%5Comega%20%3D%2010%20%5Brad%2Fs%5D%5C%5Cr%3D0.5%20%5Bm%5D%5C%5Cm%3D13%5BKg%5D)
and also the formula which states that the kinetic rotational energy of a body is:
.
Now we use the kinetic energy formula

where
is the tangential velocity of the particle. Tangential velocity is related to angular velocity by:

After replacing in the previous equation we get:

now we have the following:

therefore:

then the moment of inertia will be:
![I = 13*(0.5)^2=3.25 [Kg*m^2]](https://tex.z-dn.net/?f=I%20%3D%2013%2A%280.5%29%5E2%3D3.25%20%5BKg%2Am%5E2%5D)
Answer:
By convention a negative torque leads to clockwise rotation and a positive torque leads to counterclockwise rotation.
here weight of the child =21kgx9.8m/s2 = 205.8N
the torque exerted by the child Tc = - (1.8)(205.8) = -370.44N-m ,negative sign is inserted because this torque is clockwise and is therefore negative by convention.
torque exerted by adult Ta = 3(151) = 453N , counterclockwise torque.
net torque Tnet = -370.44+453 =82.56N , which is positive means counterclockwise rotation.
b) Ta = 2.5x151 = 377.5N-m
Tnet = -370.44+377.5 = 7.06N-m , positive ,counterclockwise rotation.
c)Ta = 2x151 = 302N-m
Tnet = -370.44+302 = -68.44N-m, negative,clockwise rotation.
Acceleration I think if I’m not mistaken
True would be the Correct answer