Day and night is due to the earth rotating. Seasons are due to the earth rotating on a slightly tilted axis, causing light to be shone on different parts of the earth more directly during different parts of the year. Constellations changing throughout the night are because of the earth moving and rotating. Throughout the year, the earth moves, causing us to be facing different directions in different parts of the year. The North Star does't move because it is close to Earth's line of axis, and therefore does not appear to move.
Answer:
★ v = d/t
★ v = 90/30
★ v =3
<u>Acc</u><u> </u><u>to</u><u> </u><u>question</u>
★ momentum = mass * velocity
★ m = 25×3
★ m = 75kgm/s
Hope it help
The electromagnet and the permanent magnet -- interact with each other as any two magnets do. The positive end of the electromagnet is attracted to the negative pole of the permanent magnetic field, and the negative pole of the electromagnet is repelled by the permanent magnet's negative pole
Answer : The temperature will be, 392.462 K
Explanation :
According to the Arrhenius equation,
or,
![\log (\frac{K_2}{K_1})=\frac{Ea}{2.303\times R}[\frac{1}{T_1}-\frac{1}{T_2}]](https://tex.z-dn.net/?f=%5Clog%20%28%5Cfrac%7BK_2%7D%7BK_1%7D%29%3D%5Cfrac%7BEa%7D%7B2.303%5Ctimes%20R%7D%5B%5Cfrac%7B1%7D%7BT_1%7D-%5Cfrac%7B1%7D%7BT_2%7D%5D)
where,
= rate constant at 
=
= rate constant at 
= 
= activation energy for the reaction = 66.41 kJ/mole = 66410 J/mole
R = gas constant = 8.314 J/mole.K
= initial temperature = 293 K
= final temperature = ?
Now put all the given values in this formula, we get:
![\log (\frac{3K_1}{K_1})=\frac{66410J/mole}{2.303\times 8.314J/mole.K}[\frac{1}{293K}-\frac{1}{T_2}]](https://tex.z-dn.net/?f=%5Clog%20%28%5Cfrac%7B3K_1%7D%7BK_1%7D%29%3D%5Cfrac%7B66410J%2Fmole%7D%7B2.303%5Ctimes%208.314J%2Fmole.K%7D%5B%5Cfrac%7B1%7D%7B293K%7D-%5Cfrac%7B1%7D%7BT_2%7D%5D)
Therefore, the temperature will be, 392.462 K
Answer:
Percent error = -22%
Explanation:
Given data:
Density of aluminium = 2.1,2.12 and 2.09 g/cm³
Accepted value of density of aluminium = 2.7 g.cm³
Percent error = ?
Solution:
First of all we will calculate the average of data measured by students.
Average value = 2.1 g/cm³ + 2.12 g/cm³+ 2.09 g/cm³ / 3
Average value = 6.31 g/cm³/ 3
Average value = 2.1 g/cm³
Now we will calculate the percent error.
Percent error = [ Measured value - accepted value / accepted value ]× 100
Percent error = [ 2.1 g/cm³ - 2.70 g/cm³ / 2.70 g/cm³ ]× 100
Percent error = [-0.6/2.70 g/cm³ ] × 100
Percent error = -0.22 × 100
Percent error = -22%
