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2 years ago

14

A force does 210 J of work when it acts on a moving object and its direction is in the same direction as the object’s displaceme

nt. How much work does this force do when the angle between it and the object’s displacement is 56°

1 answer:

MariettaO [177]2 years ago

5 0

Answer:

When the angle is 56° the work done is 117.43 J

Explanation:

Work = F . s = Fscosθ

We have

W1 = 210 J, θ = 0°

Substituting

210 = F x s x cos 0 = Fs

Now we have to find W2 when angle θ = 56°

Substituting

W2 = F x s x cos 56 = 210 cos56= 117.43 J

When the angle is 56° the work done is 117.43 J

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One problem with digital data is that it can be vulnerable to hackers.

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Answer: c. A person who gains unauthorized access to digital data

Explanation:

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1 year ago

Of the following transitions in the Bohr hydrogen atom, the ________ transition results in the absorption of the highest-energy

8_murik_8 [283]

Answer:

The <em><u>n = 2 → n = 3</u></em> transition results in the absorption of the highest-energy photon.

Explanation:

$E_n=-13.6\times \frac{Z^2}{n^2}ev$

Formula used for the radius of the $n^{th}$ orbit will be,

where,

$E_n$ = energy of $n^{th}$ orbit

n = number of orbit

Z = atomic number

Here: Z = 1 (hydrogen atom)

Energy of the first orbit in H atom .

$E_1=-13.6\times \frac{Z^2}{1^2} eV=-13.6 eV$

Energy of the second orbit in H atom .

$E_2=-13.6\times \frac{Z^2}{(2)^2} eV=-3.40 eV$

Energy of the third orbit in H atom .

$E_3=-13.6\times \frac{Z^2}{(9)^2} eV=-1.51 eV$

Energy of the fifth orbit in H atom .

$E_5=-13.6\times \frac{Z^2}{(2)^2} eV=-0.544 eV$

Energy of the sixth orbit in H atom .

$E_6=-13.6\times \frac{Z^2}{(2)^2} eV=-0.378 eV$

Energy of the seventh orbit in H atom .

$E_7=-13.6\times \frac{Z^2}{(2)^2} eV=-278 eV$

During an absorption of energy electron jumps from lower state to higher state.So, absorption will take place in :

1) n = 2 → n = 3

2) n= 5 → n = 6

Energy absorbed when: n = 2 → n = 3

$E=E_3-E_2$

$E=(-1.51 eV) -(-3.40 eV)=1.89 eV$

Energy absorbed when: n = 5 → n = 6

$E'=E_6-E_5$

$E'=(-0.378 eV)-(-0.544 eV) =0.166 eV$

1.89 eV > 0.166 eV

E> E'

So,the n = 2 → n = 3 transition results in the absorption of the highest-energy photon.

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2 years ago

6. A satellite is orbiting Earth just above its surface. The centripetal force making the satellite follow a circular trajectory

Svetllana [295]

Answer:

Engular velocity: $w=1,24*10^{-3}/s$

Linear velocity: $V=7905 m/s$

The time it takes:

$t=5060s=84min$

Explanation:

The magnitude of the centripetal acceleration can be related to the angular velocity and radius as:

(1) $a=r*w^{2}$

Solving for w:

(2) $w=\sqrt{\frac{a}{r} }$

Replacing a=9,8m/s2 and r=6,375,000m:

(3) $w=\sqrt{\frac{9,8m/s^{2}}{6375000m} }=1,24*10^{-3}/s$

And the angular velocity relates to the linear velocity:

$V=w*r=1,24*10^{-3}/s*6375000m=7905 m/s$

The perimeter of the orbit is:

$P=\pi *2*r=\pi *2*6375000m=40.05*10^{6}m$

The time it takes:

$t=\frac{P}{V} =\frac{40.05*10^{6}m}{7905 m/s}=5060s=84min$

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2 years ago

Concrete colums are constructed with reinforcing steel in them to make them stronger and more ductile. The reinforcing bars are

Sergio039 [100]

Answer:

$21678.47223\ lbf-in^2$

$383.1109\ lbf-in^2$

Explanation:

d = Diameter of column = 0.5 inch

$A_c$ = Area of concrete = $119.4\ in^2$

The strain in the system is conserved

$\dfrac{F_sL}{A_sE_s}=\dfrac{F_cL}{A_cE_c}\\\Rightarrow F_c=\dfrac{F_sA_cE_c}{A_sE_s}\\\Rightarrow F_c=\dfrac{F_s \times 119.4\times 4.1\times 10^6}{8\times \dfrac{\pi \dfrac{1}{2^2}}{4}\times 29\times 10^6}\\\Rightarrow F_c=10.74658F_s$

Now

$F_c+F_s=50000\\\Rightarrow 10.74658F_s+F_s=50000\\\Rightarrow F_s=\dfrac{50000}{11.74658}\\\Rightarrow F_s=4256.55807\ lbf$

$F_c=10.74658F_s\\\Rightarrow F_c=10.74658\times 4256.55807\\\Rightarrow F_c=45743.44182\ lbf$

Stress is given by

$\sigma_s=\dfrac{4256.55807}{\pi \dfrac{1}{2^2}}{4}\\\Rightarrow \sigma_s=21678.47223\ lbf-in^2$

The stress in the steel is $21678.47223\ lbf-in^2$

$\sigma_c=\dfrac{45743.44182}{119.4}\\\Rightarrow \sigma_s=383.1109\ lbf-in^2$

The stress in the steel is $383.1109\ lbf-in^2$

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3 years ago

What is one use for infrared waves? A radar B Medical imaging C Thermal imaging cameras

Vilka [71]

Answer:

Im answering for free points sry

Explanation:

...

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2 years ago