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Black_prince [1.1K]

4 years ago

5

It takes 63 W to power a ceiling fan. The energy output of the fan is 50 W. Calculate the efficiency of the fan. Round your answ

er to the nearest percentage. %

1 answer:

VMariaS [17]4 years ago

7 0

Answer: 79% on edg

Explanation:

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Three fire hoses are connected to a fire hydrant. Each hose has a radius of 0.017 m. Water enters the hydrant through an undergr

alexira [117]

Answer:

2.36 x 10^5 kg

Explanation:

radius of hose, r = 0.017 m

radius of underground pipe, R = 0.088 m

number of hoses, n = 3

velocity of water in underground pipe, V = 2.7 m/s

Let v is the velocity of water in each hose.

According to the equation of continuity

A x V = n x a x v

π R² x V = n x π x r² x v

0.088 x 0.088 x 2.7 = 3 x 0.017 x 0.017 x v

v = 24.12 m/s

(a) Amount of water poured onto a fire in one hour by all the three hoses

= n x a x v x density of water x time

= 3 x 3.14 x 0.017 x 0.017 x 24.12 x 1000 x 3600

= 2.36 x 10^5 kg

Thus, the amount of water poured onto the fire in one hour is 2.36 x 10^5 kg.

6 0

3 years ago

A flywheel is a solid disk that rotates about an axis that is perpendicular to the disk at its center. Rotating flywheels provid

Sergeeva-Olga [200]

Answer:

$8.37*10^5$ rpm

Explanation:

Given that rotational kinetic energy = $4.66*10^9J$

Mass of the fly wheel (m) = 19.7 kg

Radius of the fly wheel (r) = 0.351 m

Moment of inertia (I) = $\frac{1}{2} mr ^2$

Rotational K.E is illustrated as $(K.E)_{rt} = \frac{1}{2} I \omega^2$

$\omega = \sqrt{\frac{2(K.E)_{rt}}{I} }$

$\omega = \sqrt{\frac{2(KE)_{rt}}{1/2 mr^2} }$

$\omega = \sqrt{\frac{4(K.E)_{rt}}{mr^2} }$

$\omega = \sqrt{\frac{4*4.66*10^9J}{19.7kg*(0.351)^2} }$

$\omega = 87636.04$

$\omega = 8.76*10^4 rad/s$

Since 1 rpm = $\frac{2 \pi}{60} rad/s$

$\omega = 8.76*10^4(\frac{60}{2 \pi})$

$\omega = 836518.38$

$\omega = 8.37 *10^5 rpm$

3 0

3 years ago

In a nuclear power plant, the nuclear reaction is kept from going critical by keeping the rate of reaction safe. How do the cont

stepan [7]

I think its B. Sorry if Im wrong.

3 0

3 years ago

Read 2 more answers

A basketball referee tosses the ball straight up for the starting tip-off. At what velocity (in m/s) must a basket ball player l

mamaluj [8]

Answer:4.93 m/s

Explanation:

Given

height to reach is (h )1.24 m

here Let initial velocity is u

using equation of motion

$v^2-u^2=2ah$

here Final Velocity v=0

a=acceleration due to gravity

$0-u^2=2\left ( -g\right )h$

$u=\sqrt{2gh}$

$u=\sqrt{2\times 9.81\times 1.24}$

$u=\sqrt{24.328}$

u=4.93 m/s

7 0

4 years ago

A 263 g ball of clay falls onto a vertical spring.

Elena-2011 [213]

Answer:

d. According to the previous theorem:

(kh^2)/2-mgh-(m(2v)^2)/2=0,

126h^2-2.577h-8.236=0,

h=0.266 m.

Explanation:

3 0

3 years ago