Answer:
a) 24.43 radians per second
b) 268.73 inches per second
Explanation:
a) The angular speed of the fan on Celsius degrees/second is 1400, so we should convert that value to radians using the fact that 2π rad = 360 °C:


b) Linear speed on a point of the blade is related with angular speed of the fan by the equation

with v linear speed, ω angular speed and r the radius of the blades. So:

Radians isn't really a unity; it is dimensionless so we can put it or not. So:

I am not sure what this is
Answer:
(a) 1.939 m/h
(b) 0.926 m/h
(c) -0.315 m/h
(d) -1.21 m/h
Explanation:
Here, we have the water depth given by the function of time;
D(t) = 7 + 5·cos[0.503(t-6.75)]
Therefore, to find the velocity of the depth displacement with time, we differentiate the given expression with respect to time as follows;
D'(t) = ![\frac{d(7 + 5\cdot cos[0.503(t-6.75)])}{dt}](https://tex.z-dn.net/?f=%5Cfrac%7Bd%287%20%2B%205%5Ccdot%20cos%5B0.503%28t-6.75%29%5D%29%7D%7Bdt%7D)
= 5×(-sin(0.503(t-6.75))×0.503
= -2.515×(-sin(0.503(t-6.75))
= -2.515×(-sin(0.503×t-3.395))
Therefore we have;
(a) at 5:00 AM = 5 - 0:00 = 5
D'(5) = -2.515×(-sin(0.503×5-3.395)) = 1.939 m/h
(b) at 6:00 AM = 6 - 0:00 = 6
D'(5) = -2.515×(-sin(0.503×6-3.395)) = 0.926 m/h
(c) at 7:00 AM = 7 - 0:00 = 7
D'(5) = -2.515×(-sin(0.503×7-3.395)) = -0.315 m/h
(d) at Noon 12:00 PM = 12 - 0:00 = 12
D'(5) = -2.515×(-sin(0.503×12-3.395)) = -1.21 m/h.
<h2>
Answer:</h2>
<u>Friction:</u>
When an object slips on a surface, an opposing force acts between the tangent planes which acts in the opposite direction of motion. This opposing force is called Friction. Or in other words, Friction is the opposing force that opposes the motion between two surfaces.
The main component of friction are:
<u>Normal Reaction (R):
</u>
Suppose a block is placed on a table in the above picture, which is in resting state, then two forces are acting on it at that time.
The first is due to its weight mg which is working from its center of gravity towards the vertical bottom.
The second one is superimposed vertically upwards by the table on the block, called the reaction force (P). This force passes through the center of gravity of the block.
Due to P = mg, the box is in equilibrium position on the table.
<u>Coefficient of friction ( </u>μ )<u>:
</u>
The ratio of the force of friction and the reaction force is called the coefficient of friction.
Coefficient of friction, µ = force of friction / reaction force
μ = F / R
The coefficient of friction is volume less and dimensionless.
Its value is between 0 to 1.
<u>Advantage and disadvantage from friction force:
</u>
- The advantage of the force of friction is that due to friction, we can walk on the earth without slipping.
- Brakes in all vehicles are due to the force of friction.
- We can write on the board only because of the force of friction.
- The disadvantage of this force is that due to friction, some parts of energy are lost in the machines and there is wear and tear on the machines.
<u>How to reduce friction:
</u>
- Using lubricants (oil or grease) in machines.
- Friction can be reduced by using ball bearings etc.
- Using a soap solution and powder.