Answer:
The distance covered by the minutes hand is 39.60 cm.
Explanation:
Note: A clock has a circular shape, where the minutes hand acts as the radius, and its motion creates an arc.
Length of an arc is calculated as ∅/360(2πr)
L = ∅/360(2πr).................... Equation 1π
Here, L represents the arc’s length, ∅ is the angle made by the arc, and r is the arc’s radius.
Given: ∅ = 252°, r = 9 cm, π = 3.143.
Upon substituting these values into equation 1,
L = 252/360(2×3.143×9)
L = 0.7×2×3.143×9
L = 39.60 cm.
Thus, the distance traversed by the minutes hand is 39.60 cm.
The star is moving away from our planet. To elaborate on the Doppler shift: This phenomenon, related to the Doppler effect, is the variation in the perceived frequency or wavelength (color) of a wave when the source of the waves and the observer are in motion relative to one another. Consequently, it can be inferred that as an object recedes, it exhibits more redshift in its spectrum. For instance, when a star moves away, its spectral lines shift towards the red end of the spectrum, whereas if it approaches Earth, the spectral lines move towards blue. Given that the peak wavelength is roughly 650 nm—which is associated with red—it can be concluded that the star is indeed moving away from Earth.
<span>To express uncertainty as a percentage, divide the uncertainty by the measured value and multiply by 100%.
(2 m / 20,000,000 m) × 100% = 0.00001%
This means the percent uncertainty is 0.00001%.
Subtracting this from 100% gives the percent accuracy:
Percent accuracy = 100% - 0.00001% = 99.99999%
Therefore, the percent accuracy required is 99.99999%.</span>
