Answer:
Explanation:
To find the angular velocity of the tank at which the bottom of the tank is exposed
From the information given:
At rest, the initial volume of the tank is:

where;
height h which is the height for the free surface in a rotating tank is expressed as:

at the bottom surface of the tank;
r = 0, h = 0
∴
0 = 0 + C
C = 0
Thus; the free surface height in a rotating tank is:

Now; the volume of the water when the tank is rotating is:
dV = 2π × r × h × dr
Taking the integral on both sides;

replacing the value of h in equation (2); we have:


![V_f = \dfrac{ \pi \omega ^2}{g} \Big [ \dfrac{r^4}{4} \Big]^R_0](https://tex.z-dn.net/?f=V_f%20%3D%20%5Cdfrac%7B%20%5Cpi%20%5Comega%20%5E2%7D%7Bg%7D%20%5CBig%20%5B%20%20%5Cdfrac%7Br%5E4%7D%7B4%7D%20%5CBig%5D%5ER_0)
![V_f = \dfrac{ \pi \omega ^2}{g} \Big [ \dfrac{R^4}{4} \Big] --- (3)](https://tex.z-dn.net/?f=V_f%20%3D%20%5Cdfrac%7B%20%5Cpi%20%5Comega%20%5E2%7D%7Bg%7D%20%5CBig%20%5B%20%20%5Cdfrac%7BR%5E4%7D%7B4%7D%20%5CBig%5D%20---%20%283%29)
Since the volume of the water when it is at rest and when the angular speed rotates at an angular speed is equal.
Then 
Replacing equation (1) and (3)






Finally, the angular velocity of the tank at which the bottom of the tank is exposed = 10.48 rad/s
Answer:
4
Explanation:
As you can see in the free body diagram there are 4 forces acting on the body.
Answer:
B
Explanation:
Heat flows from hot to cold to lower the temperature of hot areas and increase temperature of cold areas. The end result is that the 2 areas have the same temperature, thus increasing entropy.
Answer:
F = 339.23 N
Explanation:
Weight of a car, W = 1050 N
Initial velocity, u = 0
Final velocity, v = 42 m/s
Time, t = 13 s
The weight of an object is given by :
W = mg
g is the acceleration due to gravity

The force acting on car is :

So, the force acting on the car is 339.23 N.