Answer:
Wegener first thought of this idea by noticing that the different large landmasses of the Earth almost fit together like a jigsaw puzzle. The continental shelf of the Americas fits closely to Africa and Europe, and other continents showed the same trend. Wegner also analyzed both sides of the Atlantic Ocean for rock type, geological structures and fossils and noticed that there was a significant similarity between matching sides of the continents, especially in fossil plants.
Answer:
75 rotations
Explanation:
f0 = 0, f = 3000 rpm = 50 rps, t = 3 s
(a) use first equation of motion for rotational motion
w = w0 + α t
2 x 3.14 x 50 = 0 + α x 3
α = 104.67 rad/s^2
(b) Let θ be the angular displacement
use second equation of motion for rotational motion
θ = w0 t + 1/2 α t^2
θ = 0 + 0.5 x 104.67 x 3 x 3
θ = 471.015 rad
The angle turn in one rotation is 2 π radian.
Number of rotation = 471.015 / (2 x 3.14) = 75 rotations
Answer:

Explanation:
<u>Given Data:</u>
Length = l = 820 mm = 0.82 m
Acceleration due to gravity = g = 9.8 ms⁻²
<u>Required:</u>
Frequency = f = ?
<u>Formula:</u>

<u>Solution:</u>
![\displaystyle f =\frac{1}{2 \pi} \sqrt{\frac{g}{l} } \\\\Put\ the\ givens\\\\f=\frac{1}{2 \pi} \sqrt{\frac{9.8}{0.82} }\\\\ f = 0.159 \times \sqrt{11.95} \\\\f=0.159 \times 3.457\\\\f=0.55 \ Hz\\\\\rule[225]{225}{2}](https://tex.z-dn.net/?f=%5Cdisplaystyle%20f%20%3D%5Cfrac%7B1%7D%7B2%20%5Cpi%7D%20%5Csqrt%7B%5Cfrac%7Bg%7D%7Bl%7D%20%7D%20%5C%5C%5C%5CPut%5C%20the%5C%20givens%5C%5C%5C%5Cf%3D%5Cfrac%7B1%7D%7B2%20%5Cpi%7D%20%5Csqrt%7B%5Cfrac%7B9.8%7D%7B0.82%7D%20%7D%5C%5C%5C%5C%20f%20%3D%200.159%20%5Ctimes%20%5Csqrt%7B11.95%7D%20%5C%5C%5C%5Cf%3D0.159%20%5Ctimes%203.457%5C%5C%5C%5Cf%3D0.55%20%5C%20Hz%5C%5C%5C%5C%5Crule%5B225%5D%7B225%7D%7B2%7D)
Answer:
6 m
Explanation:
velocity = wavelength x frequency
444 m/s = wavelength x 74 Hz
444 m/s / 74 Hz = wavelength
wavelength = 6m