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3 years ago

11

Radio devices are used for communication in space. Why

1 answer:

Elena-2011 [213]3 years ago

6 0

Because radio waves can travel in space but sound waves cannot.

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76.8 kPa to mm of Hg

Bumek [7]

Answer:

The answer is 576.0473

Explanation:

Hope this helps.

Please mark my answer as brainliest?

3 0

2 years ago

Consider a uniform horizontal wooden board that acts as a pedestrian bridge. The bridge has a mass of 300 kg and a length of 10

gayaneshka [121]

Answer:

F = 2123.33N

Explanation:

In order to calculate the torque applied by the left support, you take into account that the system is at equilibrium. Then, the resultant of the implied torques are zero.

$\Sigma \tau=0$

Next, you calculate the resultant of the torques around the right support, by taking into account that the torques are generated by the center of mass of the wooden, the person and the left support. Furthermore, you take into account that torques in a clockwise direction are negative and in counterclockwise are positive.

Then, you obtain the following formula:

$-\tau_l+\tau_p+\tau_{cm}=0$ (1)

τl: torque produced by the left support

τp: torque produced by the person

τcm: torque produced by the center of mass of the wooden

The torque is given by:

$\tau=Fd$ (2)

F: force applied

d: distance to the pivot of the torque, in this case, distance to the right support.

You replace the equation (2) into the equation (1) and take into account that the force applied by the person and the center of mass of the wood are the their weight:

$-Fd_1+W_pd_2+W_{cm}d_3=0\\\\d_1=6.0m\\\\d_2=2.0m\\\\d_3=3.0m\\\\W_p=(200kg)(9.8m/s^2)=1960N\\\\W_{cm}=(300kg)(9.8m/s^2)=2940N$

Where d1, d2 and d3 are distance to the right support.

You solve the equation for F and replace the values of the other parameters:

$F=\frac{W_pd_2+W_d_3}{d_1}=\frac{(1960N)(2.0m)+(2940N)(3.0m)}{6.0m}\\\\F=2123.33N$

The force applied by the left support is 2123.33 N

8 0

3 years ago

Please I need HELP WITH THIS QUESTION!!!

JulsSmile [24]

Oil, grease and dry lubricants

8 0

2 years ago

The decibel level of an orchestra is 90 db, and the violin section achieves a level of 80 dB. How does the sound intensity from

skad [1K]

Answer:

The difference in the decibel corresponses to a constant difference in the loudness perceived.

The refore the sound intensity from the orchestra is like 100 times that of the violin.

Explanation:

4 0

3 years ago

You leave the doctor's office after your annual checkup and recall that you weighed 688 N in her office. You then get into an el

Lapatulllka [165]

Answer:

$a=0.5418\ m.s^{-2}$ upwards

$a=1.283\ m.s^{-2}$ downwards

Explanation:

Given:

weight of the person, $w=688\ N$

So, the mass of the person:

$m=\frac{w}{g}$

$m=\frac{688}{9.81}$

$m=70.132\ kg$

Now if the apparent weight in the elevator, $w_a= 726\ N$

<u>Then the difference between the two weights is :</u>

$\Delta w=w_a-w$

$\Delta w=726-688$

$\Delta w=38\ N$ is the force that acts on the body which generates the acceleration.

Now the corresponding acceleration:

$a=\frac{\Delta w}{m}$

$a=\frac{38}{70.132}$

$a=0.5418\ m.s^{-2}$ upwards, because the normal reaction that due to the weight of the body is increased here.

Now if the apparent weight in the elevator, $w_a= 598\ N$

<u>Then the difference between the two weights is :</u>

$\Delta w=w-w_a$

$\Delta w=688-598$

$\Delta w=90\ N$ is the force that acts on the body which generates the acceleration.

Now the corresponding acceleration:

$a=\frac{\Delta w}{m}$

$a=\frac{90}{70.132}$

$a=1.283\ m.s^{-2}$ downwards, because the normal reaction that due to the weight of the body is decreased here.

7 0

3 years ago

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