Answer:
1426.8 N
Explanation:
Pressure, P = 3567 Pa
The area of Mr. Rosa’s foot, A = 0.4 m²
We need to find the force does one kick from Mr. Rosa create. The pressure acting due to force is given by :
where
F is force
So, the required force is 1426.8 N.
If the observer and the source are getting closer together OR getting farther apart, the observer will hear a sound with a different frequency compared to the sound that's actually coming out of the source.
An Austrian physicist and mathematician named Christian Doppler studied this effect, and he worked out the math that tells how much the frequency will change, depending on how fast the source and observer are moving, and whether they're moving together or apart.
After Doppler worked it out other scientists debated and argued for several years what they wanted to CALL this effect.
Some wanted to call it the "Freaky-Shifty Effect", because when the motion is there, the frequency of the source gets shifted.
Other scientists noticed that if the observer moves back and forth and back and forth, the frequency he hears goes up and down and up and down, and it sounds something like "OOWAH-EEYOO OOWAH-EEYOO", so THEY wanted to call it the "Y-U Effect".
After years of disagreement and debate, the cooler scientists found the best way to displease everyone. They just pointed out that it was Doppler who explained the whole thing and worked out all the math, and it would actually be nice to give him some credit for it. So everybody just cooled off and agreed to call it the <em>Doppler Effect</em> .
Answer:
lift force = 0.213 N
Drag force =
Explanation:
Given: velocity v = 10 m/s
w = 100 rev/sec
diameter d = 3cm
density D = 1.2kg/m3
lift force =
Substituting the values into the equation, we obtain
lift force = 0.213 N
Drag force = C*D*A*v/2
where C = 0.5
substituting the values into the equation again, we have
Drag force =
Answer:
C) steel turning to rust in salt air
Explanation:
The missing options are:
A) ice melting to form liquid water
B) water boiling to form steam
C) steel turning to rust in salt air
D) sugar dissolving into hot coffee
In a chemical change the atoms of the reacting compounds are reordered forming new compounds. In a chemical change, new compounds appear, but in a physical change not.
Then, change of states like ice melting and water boiling are not chemical changes.
During steel rust, components of steel, like iron, are oxidized, that is, reacts with oxygen forming oxides.
The dissolution of sugar into hot coffee is a physical change in which sugar molecules get further apart in the coffee, but they don't change.
They were both odd and obsessive