Ultraviolet radiation from the sun is controlled by the ozone but if it infiltrates into the atmosphere it becomes a hazard. The uv reaches our eyes and darkens the retina and blurs vision. The fovea becomes insensitive and the cells dormant. This causes gradual blindness.
Answer:
Explanation:
Given,
The angle of the slide=
The mass of the child is= m
coefficient of friction = 0.20
when she slides down now apply Newton's law
therefore the acceleration
![a=g[\sin \theta -\mu \cos \theta]](https://tex.z-dn.net/?f=a%3Dg%5B%5Csin%20%5Ctheta%20-%5Cmu%20%5Ccos%20%5Ctheta%5D)
![a=9.8\times [\sin 42^\circ -0.2\times \cos 42^\circ]](https://tex.z-dn.net/?f=a%3D9.8%5Ctimes%20%5B%5Csin%2042%5E%5Ccirc%20-0.2%5Ctimes%20%5Ccos%2042%5E%5Ccirc%5D)
hence, the magnitude of acceleration during her sliding is equal to
The following information are given in the question:
Mass, M = 8 g
Temperature, T = 20 degree Celsius
Specific heat of water [this value is a constant] C = 1 c/gc
Heat, Q = ?
The formula for calculating the amount of heat required is given below:
Q = MCT = 8 * 1 * 20 = 160
Therefore, Q = 160 cal.
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The radiation dose absorbed by a person is measured using the conventional unit rad or the SI unit gray. The biological risk of exposure to radiation is measured using the conventional unit rem or the SI unit sievert.
I hope this helps!
Answer:
a = 0.55 m / s²
Explanation:
The centripetal acceleration is given by the relation
a = v² / r
angular and linear velocities are related
v = w r
we substitute
a = w² r
In the exercise they indicate the angular velocity w = 1 rev/min, let's reduce to the SI system
w = 1 rev / min (2pi rad / 1rev) (1min / 60s) = 0.105 rad/ s
let's calculate
a = 0.105² 50.0
a = 0.55 m / s²
