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girlphysics
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5. A force of 12 N is applied tangentially to the rim of a wheel with radius 0.70 m and rotational inertia 3.0 kg-m2. What angular acceleration results?
a) 2.6 rad/s2 b) 2.8 rad/s2 c) 3.2 rad/s2 d) 3.4 rad/s2 e) none of these
____6. If the force in question #5 acts for 20 s, what will be the kinetic energy of the spinning wheel?
a) 4.7 x 103 j b) 4.4 x 102 j c) 4. 7 x 10 j d) 84 j e) none of the above answers is within 10 % of the correct value
I figured out number 5 to be B.) 2.8 rad/s by rF/I from Torque=Ia
For 6, when I solve using K=1/2Iw^2, and using 2.8 rad/s^2 divided by 20 seconds to get the angular velocity of .14 rad/s, I get a really small number, like .03. What am I doing wrong?
a) 2.6 rad/s2 b) 2.8 rad/s2 c) 3.2 rad/s2 d) 3.4 rad/s2 e) none of these
____6. If the force in question #5 acts for 20 s, what will be the kinetic energy of the spinning wheel?
a) 4.7 x 103 j b) 4.4 x 102 j c) 4. 7 x 10 j d) 84 j e) none of the above answers is within 10 % of the correct value
I figured out number 5 to be B.) 2.8 rad/s by rF/I from Torque=Ia
For 6, when I solve using K=1/2Iw^2, and using 2.8 rad/s^2 divided by 20 seconds to get the angular velocity of .14 rad/s, I get a really small number, like .03. What am I doing wrong?
