Answer:
C
Explanation:
Carbon dioxide should be the input, and oxygen should be the output.
No, you wouldn't do any more work by going up the stairs twice as fast.
work done is equal to : F x D
time is not included, which mean you only done the work faster, but not doing any more work compared to the slower one
hope this helps
Answer:
I'm no expert, but multitasking is a no bueno. Because multitasking reduces your efficiency and performance because your brain can only focus on one thing at a time. When you try to do two things at once, your brain lacks the capacity to perform both tasks successfully.
Therefore I would choose A, considering he could easily workout another time, whilst the test is a one time thing. He can't redo the test, but he can workout again. So my answer is A.
If he HAS to workout and study at the same time, then C would be appropriate.
I hope this helps!
Answer:

Explanation:
When a person shouts it emits 1 W of energy as sound waves, P = 1 W
Let I is the sound intensity 1 meters from such a person. We know that the power per unit area is called the sound intensity of the person. Its formula is given by :



So, the sound intensity of such a person is
. Hence, this is the required solution.
Answer:
2.58 x 10⁸ m/s
Explanation:
Time dilation fomula will be applicable here, which is given below.
t = \frac{T}{\left ( 1-\frac{v^2}{c^2} \right )^\frac{1}{2}}
Where T is dilated time or time observed by clock in motion , t is stationary time , v is velocity of clock in motion and c is velocity of light .
c is 3 times 10⁸ ms⁻¹ , T is 7.24 h , t is 3.69 h. Put these values in the formula
7.24 = \frac{3.69}{\left ( 1-\frac{v^2}{c^2} \right )^\frac{1}{2}}\\
\frac{v^2}{c^2}=0.744\\\\
v=2.58\times 10^8