Answer:
correct option is C) 2.8
Step-by-step explanation:
given data
string vibrates form = 8 loops
in water loop formed = 10 loops
solution
we consider mass of stone = m
string length = l
frequency of tuning = f
volume = v
density of stone =
case (1)
when 8 loop form with 2 adjacent node is
so here
..............1

and we know velocity is express as
velocity = frequency × wavelength .....................2
= f ×
here tension = mg
so
= f ×
..........................3
and
case (2)
when 8 loop form with 2 adjacent node is
..............4

when block is immersed
equilibrium eq will be
Tenion + force of buoyancy = mg
T + v ×
× g = mg
and
T = v ×
- v ×
× g
from equation 2
f ×
= f ×
.......................5
now we divide eq 5 by the eq 3

solve irt we get

so
relative density 
relative density = 2.78 ≈ 2.8
so correct option is C) 2.8
So there is this chart my teacher showed me to help find the answers to your questions I will send a picture but here are the answers
30km is 18.642m
44,000in is 111760cm
21ft is 6.401m
0.75m I’m not for sure sorry but
133yards is 121615.2mm
I hope that helps sorry I did not understand the one question 0.75m
Step-by-step explanation:
i was busy so i did this much ...will solve later
12.5 because 400/32 is 12.5 lol I used a calculator
answer
no change
We've now found that there was (surprisingly) no change in the rectangle's area, despite changing its size.
Step-by-step explanation: