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1 year ago

12

Why does the Earth have gravity?

1 answer:

Mumz [18]1 year ago

6 0

Answer:

All its mass makes a combined gravitational pull on all the mass in your body.

Explanation:

Basically anything with mass has gravity

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In which scenario does radiation occur?

Airida [17]

Suntanning outside or in tanning booths are both examples.

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3 years ago

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One hundred turns of (insulated) copper wire are wrapped around a wooden cylindrical core of cross-sectional area 1.32 × 10-3 m2

kenny6666 [7]

Answer:

The charge flos through the coil is 0.023C

Explanation:

To solve this problem, it is necessary to apply the concepts related to Faraday's Law in which it is possible to calculate the emf Voltage induced due to a charge in a magnetic field

and Ohm's Law for the calculation of the current based on a given load over time.

Our data are given by:

$N=100$

$A= 1.32*10^{-3}m^2$

$R=15\Omega$

Where

N is the number of loops, A the area and R the Resistance.

The change in magnetic field can be calculated as,

$dB = 1.31-(-1.31)$

$dB = 2.62T$

The Faraday's law of electromagnetic induction is given by definition as,

$V = NA \frac{dB}{dt}$

In the other hand Ohm's law says:

$V = IR$

$V = \frac{dq}{dt} R$

Equating both equations we have

$\frac{dq}{dt} R = NA \frac{dB}{dt}$

We can re-arrange the equations to solve q, then

$dq = \frac{NA(dB)}{R}$

$q = \frac{(100)(1.32*10^{-3})(2.62)}{15}$

$q = 0.023C$

Therefore the charge flos through the coil is 0.023C

8 0

3 years ago

Three cables AB, AC, and AD are supporting a 70-m tall tower. The magnitude of force in each cable is 2 kN. Find the total force

Mrac [35]

Explanation:

The coordinates of points are:

A (0, 70, 0), B (40, 0, 0), C (40, 0, 40) D (60, 0, 60).

The position vectors for corresponding cables are:

$r_{AD} =(-60-0)i+(0-70)j+(-60-0)k\\r_{AD} =-60i-70j-60k\\r_{AC} =(-40-0)i+(0-70)j+(40-0)k\\r_{AC} =-40i-70j+40k$

$r_{AB} =(40-0)i+(0-70)j+(0-0)k\\r_{AB} =40i-70j+0k$

the unit vectors for these positions are:

$u_{AD} =r_{AD} /[r_{AD} ]=(-60/110)i-(70/110)j-(60/110)k\\=-0.5455i-0.6364j-0.5455k$

$u_{AC} =r_{AC} /[r_{AC} ]=-(40/90)i-(70/90)j+(40/90)k\\=-0.444i-0.778j+0.444k$

$u_{AB} =r_{AB}/[ r_{AB} ]=(40/80.6)j-(70/80.6)j+0k\\=0.4963i-0.8685j+0k$

The factors are:

$F_{AB} =[F_{AB} ]u_{AB} =0.9926i-1.737j+0k\\\\F_{AC}= [F_{AC]} u_{AC} =-0.8888i-1.5556j+0.8888k$

$F_{AD} =[F_{AD}] u_{AD} =-1.0910i-1.2728j-1.0910k$

so The resultant force exerted on tower by cables are:

$F_{R} =F_{AB}+ F_{AC}+ F_{AD} \\=-0.9875i-4.5648j-0.2020k\\magnitude=[F_{R} ]=4.674kN$

6 0

4 years ago

On a 150 m straight sprint, a cyclist accelerates from rest for 4.5 s at 3.8 m/s2. How long will it take her to complete the 150

balu736 [363]

Answer:

It takes 6.52 s to complete the 150 m track.

Explanation:

Let's find the position of the cyclist during the acceleration.

$x_{1}=v_{0}t+0.5at^{2}$

$x_{1}=0.5(3.8)(4.5)^{2}$

$x_{1}=38.48\: m$

Now, the final speed at this distance will be:

$v_{f}=v_{0}+at$

$v_{f}=3.8*4.5$

$v_{f}=17.1\: m/s$

Now, we know that x(tot) = 150 m, the remaining part will be:

$x_{2}=150-38.48=111.5\: m$

Therefore, the time is:

$t=\frac{x_{2}}{V_{f}}$

$t=\frac{111.5}{17.1}$

$t=6.52\: s$

I hope it helps you!

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3 years ago

Which phrase best completes the following analogy? Health is to wellness as exercise is to _____. anxiety fatigue physical fitne

Andru [333]

The better health you have, the higher wellness you'll enjoy. Thus, the more exercise you do, the better fitness you'll have.

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3 years ago

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