UESTION 1 A liywheel is a solid disk that rotates about an axis that is perpendi
ID: 1789612 • Letter: U
Question
UESTION 1 A liywheel is a solid disk that rotates about an axis that is perpendicular to the disk at its center. Rotating provide a means for storing energy in the form of rotational kinetic energy and are being considered as alternative to batteries in electric cars. The gasoline burned in a 474-mile trip in a typical x 109 J of energy. How fast would a 39.7-kg flywheel with a radius of 0.59 Give your answer in rev/min. a possible midsize car produces about 2.75 2 m have to rotate to store this much energy? UESTION 2 A helicopter has two blades (see figure), each of which has a mass of 230 kg and can be approximated as a thin rod of length 6. blades about the axis of rotation? 7 m. The blades are rotating at an angular speed of 49 rad/s. (a) What is the total moment of inertia of the two UESTION 3 A helicopter has two blades (see figure), each of which has a mass of 230 kg and can be approximated as a thin rod of length 6.7 m. The blades are rotating at an angular speed of 49 rad/s. Determine the rotational kinetic energy of the spinning blades, now the moment of inertia ofthe blades UESTION 4 1.2 A playground carousel is rotating counterclockwise about its center on frictionless bearings. A person standing still on the ground grabs onto one of the bars on the carousel very close to its outer edge and climbs aboard. Thus, this person begins with an angular speed of zero and ends up with a nonzero angular speed, which means that he underwent a counterclockwise angular acceleration. The carousel has a radius of 1.65 m, an initial angular speed of 3.03 rad/s, and a moment of inertia of 125 kg-m2. The mass of the person is 45.8 kg. Find the final angular speed of the carousel after the person climbs aboard.Explanation / Answer
1.
Moment of inertia of flywheel
I=(1/2)MR2=(1/2)*39.7*0.5922=6.96 Kg-m2
since rotational kinetic energy is given by
K=(1/2)IW2
(2.75*109)=(1/2)*(6.96)*W2
W=2.81*104 rad/sec
in revolution/minute
W=(2.81*104)*(60/2pi)
W=268504 rev/min =2.685*105 rev/min
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.