Usain Bolt I think, sorry if it’s not right
As long as all the waves stay in the same medium, the intensity of
any waves ... electromagnetic or mechanical ... decrease in proportion
to the square of the distance.
If the distance increases to 3 x the original distance, then the intensity
changes to 1/3² or 1/9 of the original intensity.
I suppose choice-'d' is the correct one, but I have to tell you that
the phrase "nine times as low" is mathematically meaningless,
and it really grinds my gears.
Answer: mass for Pyrex glass 84.21g
mass for sand 61.6g
mass for ethanol 41.32g
mass for water 62.07g
Explanation
By definition specific heat is the amount of heat required to change the temperature of 1 kg mas by 1°C
Q=mcΔT is formula for specific heat
Q is heat transfer
m is mass
ΔT is change in temperature
c is specific heat
c of Pyrex glass= 0.75 j/g°C
c of sand = 0.84 j/g°C
c of ethanol= 2.42 j/g°C
c of water = 4.18 j/g°C
now we will make M(mass) the subject, so equation becomes
m=Q/cΔT
for
pyrex glass T<em>f=</em>55.4°C
m=1920/(55.4-25)*0.75
m=84.21g {after cutting J(joules) and °C we are left with g(grams)}
for
sand T<em>f</em>=62.1°C
m=1920/(62.1-25)*0.84
m=61.6g {after cutting J(joules) and °C we are left with g(grams)}
for
ethanol T<em>f</em>=44.2°C
m=1920/(44.2-25)*2.42
m=41.32g {after cutting J(joules) and °C we are left with g(grams)}
for
water T<em>f=</em>32.4°
m=1920/(32.4-25)*4.18
m=62.07g {after cutting J(joules) and °C we are left with g(grams)}
i hope you understand the solution, thank you.
Frequency=1/T, where T is the time period.
Reciprocal of frequency = T or it can be written as T = 1/f, where f is frequency.
Answer:
= 2 beats per seconds
Explanation:
- From |f -f'| = modulus of the difference between the frequency given.
- Difference between the frequency will give us the number of beat per seconds.
These also shows how to get the period of the tuning forks.