- #1
xobeckynoel
- 2
- 0
1. A merry go round (1000kg) initially at rest with a diameter of 4m is pushed with a tangential force of 500N for 10s. Find the angular velocity, angular momentum, and rotational kinetic energy. After this, a little girl (mass - 1 kg) is placed on the rim of the merry go round.. Calculate the final rKE, final angular velocity, and what fraction of the initial rotational KE is lost as heat.
2. I used-
s = r x theta
F = ma
v = d/t
a = v/t
c = pi x d
angular velocity (w) = theta / t
angular momentum (L) = Inertia / w
rKE = 1/2 I w^2
3. By using the basic kinematic equations I got that d = 50m, and then calculated that to be 25 radians. I found theta to be 12.5 radians, and then using the equations found w = 1.25 radians/sec, L = 2500 Nxmxs, and KE = 1562.5 J.
For part B, it says to assume the little girl is a point mass- I am assuming she will decrease the acceleration because she increases the mass... but then I'm still missing time variables. HELP!
2. I used-
s = r x theta
F = ma
v = d/t
a = v/t
c = pi x d
angular velocity (w) = theta / t
angular momentum (L) = Inertia / w
rKE = 1/2 I w^2
3. By using the basic kinematic equations I got that d = 50m, and then calculated that to be 25 radians. I found theta to be 12.5 radians, and then using the equations found w = 1.25 radians/sec, L = 2500 Nxmxs, and KE = 1562.5 J.
For part B, it says to assume the little girl is a point mass- I am assuming she will decrease the acceleration because she increases the mass... but then I'm still missing time variables. HELP!