Answer:
20 meters
Step-by-step explanation:
Firstly we need to know that distance = speed * time
In this particular question, we have the time and the speed, we are only told to find the distance.
Now as we can see, the units are not consistent. While the average speed is 30mph, the time is not in hours but minutes. So practically, we have to convert the time to hours.
Since there are 60 minutes in an hour, the number of hours in 40 minutes would be 40/60 = 2/3 hours.
Now we can proceed to find the distance. We simply multiply the average speed with the time.
Hence, that is 30 * 2/3 = 20 meters
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
Answer:
D
Step-by-step explanation:
Given the 2 equations
4x - 5y = 18 → (1)
3x - 2y = 10 → (2)
Multiplying (1) by 3 and (2) by - 4, then adding will eliminate the x- term
12x - 15y = 54 → (3)
- 12x + 8y = - 40 → (4)
Add (3) and (4) term by term to eliminate x, that is
- 7y = 14 ( divide both sides by - 7 )
y = - 2
Substitute y = - 2 into either of the 2 equations and solve for x
Substituting into (1)
4x - 5(- 2) = 18
4x + 10 = 18 ( subtract 10 from both sides )
4x = 8 ( divide both sides by 4 )
x = 2
solution is (2, - 2 ) → D
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