How many wavelengths of a wave pass a point if the frequency of the wave is 4 hertz?

Motion maps for two objects, Y & Z, are shown.

serg [7]

Answer: it’s 3 seconds

Explanation:

5 0

2 years ago

you kick a soccer ball straight up into the air with a speed of 21.2 m/s how long does it take the soccer ball to reach its high

skelet666 [1.2K]

i just had this question and i totally guessed. it was 2.2.

6 0

3 years ago

A centrifugal pump rotates at n˙ = 740 rpm. Suppose the pump has some swirl at the inlet (α1 = 10°) and exits at an angle of 35°

Blizzard [7]

Answer:

Net head = 380cm

bhp = 17.710kW

Explanation:

Angular velocity of centrifugal pump:

$w=\frac{2\pi n}{60}=\frac{2\pi (750)}{60}=78.54\frac{rad}{s}$

Normal velocity component at outlet of pump:

$V_{2,n}=\frac{V}{2\pi r_{2}b_{2}}=\frac{0.573}{2\pi (0.24)(0.162)}}=2.346\frac{m}{s}$

Tangential velocity component at exit of the pump:

$V_{2,t}=v_{2,n}tan\alpha _{2}=(2.346)tan(35)=1.643\frac{m}{s}$

Normal velocity component at inlet of pump:

$V_{1,n}=\frac{V}{2\pi r_{1} b_{1}}=\frac{0.573}{2\pi (0.12)(0.18)}=4.22\frac{m}{s}$

Tangential velocity component at inlet of the pump:

$V_{1,t}=v_{1,n}tan\alpha _{1}=(4.22)tan(0)=0\frac{m}{s}$

Equivalent head in centimetre of water column:

$H_{water}=H(\frac{rho_{air}}{rho_{water}})\\\\H_{water}=(\frac{w}{g} )(r_{2}V_{2,t}-r_{1}V_{1,t})(\frac{rho_{air}}{rho_{water}}) \\\\H_{water}=(\frac{78.54}{9.81})((0.24)(1.643)-(0.12)(0)})(\frac{1.2}{998})=38m=380cm$

Break horse power:

$bhp=rho_{water} gHV=rho_{water} g[(\frac{w}{g})(r_{2}V_{2,t}-r_{1}V_{1,t})]V\\\\bhp=(998)(9.81)[(\frac{78.54}{9.81})((0.24)(1.643)-(0.12)(0))](0.573)=17710W=17.710kW$

8 0

3 years ago

When conducting an investigation to determine which type of fertilizer produces the most flowers on a plant, which variable woul

kari74 [83]

I think the answer is A. Type of fertilizer

8 0

3 years ago

what nuclear fission and nuclear fusion have in common? A. They’re both used in power plants B. they have less mass than their r

arsen [322]

A. They’re both used in power plants . . . No.

Nuclear fission is used in all nuclear power plants. Fusion isn't used in any power plants yet, because we can't control it safely enough yet. The only thing we can use nuclear fusion for is still bombs.

B. they have less mass than their reactants . . . No.

Fission involves breaking atoms into pieces. Its products have less mass than its raw materials. Fusion involves sticking atoms together to make new ones. Its products have more mass than its raw materials. Whatever the incomplete statement ' B ' is trying to say, it's not true of both processes.

B. ==> If you try really hard, this statement (B) can be undertood as true. The TOTAL MASS after both a fission reaction and a fusion reaction is less than the total mass of whatever was fissled or fuzled. In both cases, the missing mass is accounted for by the energy that was radiated from the site of the nuclear reaction.

But the statement in ' B ' is very poorly written. When you read it, you don't know what 'they' refers to.

C. they start with the same reactants . . . No.

Man-made fission starts with the heaviest atoms ... Uranium and Plutonium. Man-made fusion starts with the lightest atoms ... Hydrogen.

D. their products have more mass than their reactants ... No.

Fission breaks heavy atoms and makes lighter ones. Fusion glues light atoms and makes heavier ones.

Gee whiz ! None of the choices is correct.

7 0

3 years ago

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