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The earth’s radius is 6.37×106m; it rotates once every 24 hours. What is the earth’s angular speed? What is the speed of a point on the equa
Question
The earth’s radius is 6.37×106m; it rotates once every 24 hours. What is the earth’s angular speed? What is the speed of a point on the equator? What is the speed of a point on the earth’s surface located at 1/5 of the length of the arc between the equator and the pole, measured from equator? (Hint: what is the radius of the circle in which the point moves?)
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Physics
5 years
2021-08-10T17:10:49+00:00
2021-08-10T17:10:49+00:00 1 Answers
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Answers ( )
Answer:
a) w = 7.27 * 10^-5 rad/s
b) v1 = 463.1 m/s
c) v1 = 440.433 m/s
Explanation:
Given:-
– The radius of the earth, R = 6.37 * 10 ^6 m
– The time period for 1 revolution T = 24 hrs
Find:
What is the earth’s angular speed?
What is the speed of a point on the equator?
What is the speed of a point on the earth’s surface located at 1/5 of the length of the arc between the equator and the pole, measured from equator?
Solution:
– The angular speed w of the earth can be related with the Time period T of the earth revolution by:
w = 2π / T
w = 2π / 24*3600
w = 7.27 * 10^-5 rad/s
– The speed of the point on the equator v1 can be determined from the linear and rotational motion kinematic relation.
v1 = R*w
v1 = (6.37 * 10 ^6)*(7.27 * 10^-5)
v1 = 463.1 m/s
– The angle θ subtended by a point on earth’s surface 1/5 th between the equator and the pole wrt equator is.
π/2 ……….. s
x ………… 1/5 s
x = π/2*5 = 18°
– The radius of the earth R’ at point where θ = 18° from the equator is:
R’ = R*cos(18)
R’ = (6.37 * 10 ^6)*cos(18)
R’ = 6058230.0088 m
– The speed of the point where θ = 18° from the equator v2 can be determined from the linear and rotational motion kinematic relation.
v2 = R’*w
v2 = (6058230.0088)*(7.27 * 10^-5)
v2 = 440.433 m/s