Answer:
v = 4.1 m/s
Explanation:
As per mechanical energy conservation law we can say that initial total gravitational potential energy of the sphere is equal to final kinetic energy of rolling
so we will say
![mgh = \frac{1}{2}mv^2 + \frac{1}{2}I\omega^2](https://tex.z-dn.net/?f=mgh%20%3D%20%5Cfrac%7B1%7D%7B2%7Dmv%5E2%20%2B%20%5Cfrac%7B1%7D%7B2%7DI%5Comega%5E2)
now for pure rolling condition we know that
![v = R\omega](https://tex.z-dn.net/?f=v%20%3D%20R%5Comega)
so we will have
![mgh = \frac{1}{2}mv^2 + \frac{1}{2}(\frac{2}{5}mR^2)(\frac{v^2}{R^2})](https://tex.z-dn.net/?f=mgh%20%3D%20%5Cfrac%7B1%7D%7B2%7Dmv%5E2%20%2B%20%5Cfrac%7B1%7D%7B2%7D%28%5Cfrac%7B2%7D%7B5%7DmR%5E2%29%28%5Cfrac%7Bv%5E2%7D%7BR%5E2%7D%29)
![mgh = \frac{7}{10}mv^2](https://tex.z-dn.net/?f=mgh%20%3D%20%5Cfrac%7B7%7D%7B10%7Dmv%5E2)
now we will have
![v^2 = \sqrt{\frac{10}{7}gh}](https://tex.z-dn.net/?f=v%5E2%20%3D%20%5Csqrt%7B%5Cfrac%7B10%7D%7B7%7Dgh%7D)
![v^2 = \sqrt{\frac{10}{7}(9.8)(1.2)}](https://tex.z-dn.net/?f=v%5E2%20%3D%20%5Csqrt%7B%5Cfrac%7B10%7D%7B7%7D%289.8%29%281.2%29%7D)
![v = 4.1 m/s](https://tex.z-dn.net/?f=v%20%3D%204.1%20m%2Fs)
Well lets see, an ocean drying up is one, or another is that an earth quake flattened it. If this is an a b c or d question can I see the possible answers?
Answer:
mass can be expressed in newtons
Answer:
0.79
Explanation:
Using Snell's law, we have that:
n(1) * sin θ1 = n(2) * sinθ2
Where n(1) = refractive index of air = 1.0003
θ1 = angle of incidence
n(2) = refractive index of second substance
θ2 = angle of refraction
The angle of reflection through the unknown substance is the same as the angle of incidence of air. This means that θ1 = 32°
=> 1.0003 * sin32 = n(2) * sin42
n(2) = (1.0003 * sin32) / sin42
n(2) = 0.79