Ans:-
Question 7
Given data:w1 = 0 rev/s ,w2 = 0.10rev/s ∆t= 26.9s
α =∆w/∆t
= w2 –w1/∆t
= (0.10-0)rev/s/26.9s
α =3.72*10^-3rev/s^2
but we have to acceleration in rad/s^2
so we know that 1rev = 2π
α =3.72*10^-3*2πrad/rev
α = 0.023rad/s^2
Question 8
L= 186m, t= 2h= 2*60= 120m=120*60= 7200s, R01 = 40mm, Ri = 13mm,
Velocity V= L/t = 186m/7200s = 0.0258m/s
Angular speed w = v/r
V= w*r
Assume each reel has the same inner radius (Ri). Find the disk
area occupied by the full reel and then distribute it such that
both reels have the same outer radius:
Ro1 is the initial outer radius. Ro2 is the reel balanced outer
radius
A_tape_full = Pi*(Ro1^2 - Ri^2)
2*A_tape_balance = A_tape_full, because the tape is balanced among
the two reels
A_tape_balance = Pi*(Ro2^2 - Ri^2)
2*Pi*(Ro2^2 - Ri^2) = Pi*(Ro1^2 - Ri^2)
Solve for Ro2:
Ro2 = 1/2*sqrt(2*Ri^2 + 2*Ro1^2)
R02 = ½ *sqrt (2*( 13*10^-3)^2 + 2*(40*10^-3)^2)
R02= 0.030
W = V/R02 = 0.0258/0.030
W = 0.86rad/s
Question 9
Given data : v= 14.3m/s, a= -1.67m/s^2 , r= 0.12m
Here we use the kinematics equation
use v^2 = u^2 + 2as to find the distance travelled
0 = 14.3^2 + 2(-1.67)s
s = 14.3^2/3.34
= 61.23m
Circumference of wheels = 2πr
= 2π (0.12) m
= 0.7536
Number of revolutions = 61.23/0.7536
= 81.25
approximately 81 revolutions
answer 7,8, and 9 :) pls 007 10.0 points A potter's wheel moves from rest to...
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007 10.0 points A potter's wheel moves from rest to an angu lar speed of 0.10 rev/s in 38.5 s Assuming constant angular acceleration, what is its angular acceleration in rad/s2? Answer in units of rad/s
007 10.0 points A potter's wheel moves from rest to an angu- lar speed of 0.10 rev/s in 26.9 s. Assuming constant angular acceleration, what is its angular acceleration in rad/s7 2 Answer in units of rad/s
008 10.0 points The tape in a videotape cassette has a tota length 190 m and can play for 2.5 h. As th tape starts to play, the full reel has an oute radius of 36 mm and an inner radius of 14 mm At some point during the play, both reels wi have the same angular speed. What is this common angular speed? Answer in units of rad/s.
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A potter's wheel moves uniformly from rest to an angular speed of 0.22 rev/s in 30.0 s. A potter's wheel moves uniformly from rest to an angular speed of 0.22 rev/s in 30.0 s. (a) Find its angular acceleration in radians per second per second. rad/s2 (b) Would doubling the angular acceleration during the given period have doubled final angular speed? Yes No
answer 1 2 and 3 001 10.0 points A car accelerates uniformly from rest and reaches a speed of 17.4 m/s in 14.1 s. The diameter of a tire is 85.4 cm Find the number of revolutions the tire makes during this motion, assuming no slip- ping. Answer in units of rev. 002 10.0 points A figure skater begins spinning counterclock- wise at an angular speed of 4.5 π rad/s. Dur- ing a 4.6 s interval, she slowly pulls her...
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