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Pachacha [2.7K]

3 years ago

8

Measurements of the earth's magnetic field have been recorded since?

1 answer:

barxatty [35]3 years ago

4 0

Measurements of the Earths magnetic field has been recorded since 1829

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Pls help me, tomorrow is the deadline of my assignment

elena-14-01-66 [18.8K]

Answer:

6- B

7- I think A

8-B

9-D

10-A

3 0

2 years ago

A heavier car is always safer in a crash than a lighter car.

kvv77 [185]

Answer:

not true because the mass from the heavy car will cause it to damage more

Explanation:

4 0

3 years ago

If a dog walks north for 10 meters and then east for 10 meters, what is the direction of its displacement?

Katyanochek1 [597]

The direction of its displacement wil be

c.northeast

In fact, the dog walks north for 10 meters and east for another 10 meters. The path of the dog can be represented with two vectors, A pointing north (of magnitude 10 meters) and B pointing east (of magnitude 10 meters). The direction of the resultant vector (due to east) will be given by

$tan \theta =\frac{A}{B}=\frac{10}{10}=1$

$\theta=tan^{-1} (1)=45^{\circ}$

and the direction will be north-east.

5 0

3 years ago

What is pitch related to?

Jlenok [28]

Pitch is related to frequency

7 0

3 years ago

Say that you are in a large room at temperature TC = 300 K. Someone gives you a pot of hot soup at a temperature of TH = 340 K.

DiKsa [7]

Answer:0.061

Explanation:

Given

$T_C=300 k$

Temperature of soup $T_H=340 K$

heat capacity of soup $c_v=33 J/K$

Here Temperature of soup is constantly decreasing

suppose T is the temperature of soup at any instant

efficiency is given by

$\eta =\frac{dW}{Q}=1-\frac{T_C}{T}$

$dW=Q(1-\frac{T_C}{T})$

$dW=c_v(1-\frac{T_C}{T})dT$

integrating From $T_H$ to $T_C$

$\int dW=\int_{T_C}^{T_H}c_v(1-\frac{T_C}{T})dT$

$W=\int_{T_C}^{T_H}33\cdot (1-\frac{300}{T})dT$

$W=c_v\left [ T-T_C\ln T\right ]_{T_H}^{T_C}$

$W=c_v\left [ \left ( T_C-T_H\right )-T_C\left ( \ln \frac{T_C}{T_H}\right )\right ]$

Now heat lost by soup is given by

$Q=c_v(T_C-T_H)$

Fraction of the total heat that is lost by the soup can be turned is given by

$=\frac{W}{Q}$

$=\frac{c_v\left [ \left ( T_C-T_H\right )-T_C\left ( \ln \frac{T_C}{T_H}\right )\right ]}{c_v(T_C-T_H)}$

$=\frac{T_C-T_H-T_C\ln (\frac{T_C}{T_H})}{T_C-T_H}$

$=\frac{300-340-300\ln (\frac{300}{340})}{300-340}$

$=\frac{-40+37.548}{-40}$

$=0.061$

4 0

3 years ago