problem_sample_exam2

problem_sample_exam2 - From Chapter 5 8.8.A wheel is...

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From Chapter 5 8.8.A wheel is rotating at a rate of 2.0 revolutions every 3.0 s. Through what angle, in radians, does the wheel rotate in 1.0 s? = t, with in radians, in radians/s and t in seconds 2.0 revolutions in radians will be 2x2 p radians accomplished in 3 s, so will be The angle of rotation in 1 second 2x2 p /3.0s = 4 p /3.0s =4.19 rd 12.14. .The rotor in an amusement park ride where people stand against the inside of a cylinder. Once the cylinder is spinning fast enough, the floor drops out. (a) What force keeps the people from falling out the bottom of the cylinder? (b) If the coefficient of friction is 0.40 and the cylinder has a radius of 2.5 m, what is the minimum angular speed of the cylinder so that the people don’t fall out? (Normally the operator runs it considerably faster as a safety measure.) a) the force of static friction b) using Newton’s law SF r =N = ma r = m v 2 /r = m 2 r but fs= mg = μN=μma r =μ m 2 r = mg =v(g/μr)=v(9.8m/s 2 /(0.40*2.5m) =3.1 rad/s 14.16.(*)Earth’s orbit around the Sun is nearly circular. The period is 1 yr = 365.25 days. (a) In an elapsed time of 1 day, what is Earth’s an gular displacement? (b) What is the change in Earth’s velocity, v r ? (c) What is Earth’s average acceleration during 1
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This note was uploaded on 12/14/2011 for the course PHY 14434 taught by Professor Huang during the Spring '09 term at Wayne State University.

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problem_sample_exam2 - From Chapter 5 8.8.A wheel is...

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