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a_sh-v [17]
3 years ago
8

A physics student spends part of her day walking between classes or for recreation, during which time she expends energy at an a

verage rate of 280 W. The remainder of the day she is sitting in class, studying or resting; during these activities, she expends energy at a rate of 100 W. If she expends a total of 1.1 x 10^7 J of energy in a 24 hour day, how much of the day did she spend walking
Physics
1 answer:
kondor19780726 [428]3 years ago
7 0
RESULT: Twalk= 3.64 hr

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If you drop a 0.05 kg egg from 2m, what do you predict would be the velocity of the egg before it hits the ground, neglecting ai
Ratling [72]

Explanation:

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A) A wire made from iron with a cross-section of diameter 0.800 mm carries a current of 14.0 A. Calculate the "areal current den
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Answer:

A) ρ=1.74x10^{26}

B) μ=1.68x10^{29}\frac{electron}{m^3}

C) v=1.03x10^{-3}\frac{m}{s}

D)e=8.99x10^-9

Explanation:

A)

The magnetic field can be find knowing the current is the charge per second

β= \frac{14eC*s}{1.6x10^{-19}C}\\

β= 8.75x10^{19}e*s

Electron density

ρ=\frac{8.75x10^{19}}{\pi*0.400x10^{-3}m} = 1.74x10^{26}

B)

μ= \frac{7.86}{56.2}\frac{g}{cm^3} \frac{mol}{g}*6.022x10^{23}\frac{molecules}{mol} *2 \frac{electron}{molecule}

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C)

The drift speed using last information found

v= \frac{J}{n*q} \\v= \frac{14A}{\pi*((0.40x10^-3)^2)*1.68x10^29*1.60x10^-19)} = 1.03x10^-3(\frac{m}{s} )

D)

To compared the random thermal motion and the current's drift speed

e=\frac{1.03x10^-3}{1.15x10^5} = 8.99x10^-9

8 0
3 years ago
A model airplane with a mass of 0.741kg is tethered by a wire so that it flies in a circle 30.9 m in radius. The airplane engine
Tju [1.3M]

Answer:

_T}=24.57Nm

ω = 0.0347 rad/s²

a ≅ 1.07 m/s²

Explanation:

Given that:

mass of the model airplane = 0.741 kg

radius of the wire = 30.9 m

Force = 0.795 N

The torque produced by the net thrust about the center of the circle can be calculated as:

_T } = Fr

where;

F represent the magnitude of the thrust

r represent the radius of the wire

Since we have our parameters in set, the next thing to do is to replace it into the above formula;

So;

_T}=(0.795)*(30.9)

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(b)

Find the angular acceleration of the airplane when it is in level flight rad/s²

_T}=I \omega

where;

I = moment of inertia

ω = angular acceleration

The moment of inertia (I) can also be illustrated as:

I = mr^2

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I = 0.741 × 954.81

I = 707.51 Kg.m²

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Making angular acceleration the subject of the formula; we have;

\omega = \frac{_T}{I}

ω = \frac{24.57}{707.51}

ω = 0.0347 rad/s²

(c)

Find the linear acceleration of the airplane tangent to its flight path.m/s²

the linear acceleration (a) can be given as:

a =  ωr

a = 0.0347 × 30.9

a = 1.07223 m/s²

a ≅ 1.07 m/s²

5 0
3 years ago
Solve -7= sqrt 2x-9​
Sauron [17]

Answer:

x = 2

Explanation:

if it was -7 = the square root of both 2x-9 together, it would be false.

if it was square root of just 2x in the equation, the answer is:

x = 2

°°°°°°°°°

-7 = √2x - 9

-√2x = -9 + 7

√-2x = -2

√2x = 2

2x = 4

x = 2

4 0
3 years ago
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