Answer:
The SI unit of intensity is the watt per square meter/metre (W/m^2.)
Explanation:
Intensity is equal to the power transferred per unit area. Since power is measured in watts (W) and 1 W = 1 J/s, then intensity can be viewed as how fast energy goes through a certain area.
In physics, intensity is often used when studying light, sound, or other phenomena that involve waves or energy transfer. (With waves, the power value is taken as the average power transfer over the wave's period.)
Answer:
Friction, normal force, and weight
Explanation:
If the book slows down, it means that there must be friction acting in the opposite direction of the direction the book is moving in.
Weight is caused by the gravitational pull of the Earth on the book, and normal force is the table pushing the book up because the book is pushing down on the table (3rd law.)
Note that weight and normal force is not the 3rd law action-reaction pair. The pair is the force of the book on the table and the force of the table on the book.
Answer:
0.231 N
Explanation:
To get from rest to angular speed of 6.37 rad/s within 9.87s, the angular acceleration of the rod must be
![\alpha = \frac{\theta}{t} = \frac{6.37}{9.87} = 0.6454 rad/s^2](https://tex.z-dn.net/?f=%5Calpha%20%3D%20%5Cfrac%7B%5Ctheta%7D%7Bt%7D%20%3D%20%5Cfrac%7B6.37%7D%7B9.87%7D%20%3D%200.6454%20rad%2Fs%5E2)
If the rod is rotating about a perpendicular axis at one of its end, then it's momentum inertia must be:
![I = \frac{mL^2}{3} = \frac{1.27*0.847^2}{3} = 0.303kgm^2](https://tex.z-dn.net/?f=%20I%20%3D%20%5Cfrac%7BmL%5E2%7D%7B3%7D%20%3D%20%5Cfrac%7B1.27%2A0.847%5E2%7D%7B3%7D%20%3D%200.303kgm%5E2)
According to Newton 2nd law, the torque required to exert on this rod to achieve such angular acceleration is
![T = I\alpha = 0.303*0.6454 = 0.196 Nm](https://tex.z-dn.net/?f=%20T%20%3D%20I%5Calpha%20%3D%200.303%2A0.6454%20%3D%200.196%20Nm)
So the force acting on the other end to generate this torque mush be:
![F = \frac{T}{L} = \frac{0.196}{0.847} = 0.231 N](https://tex.z-dn.net/?f=%20F%20%3D%20%5Cfrac%7BT%7D%7BL%7D%20%3D%20%5Cfrac%7B0.196%7D%7B0.847%7D%20%3D%200.231%20N)
2 oxygen atoms are used to bond with sulfer