Answer:
ρ = 1.13 10⁴ km/m³
Explanation:
For this exercise we use Newton's equilibrium equation
B –W + W_scale = 0
Where B is the thrust and W_scale is the balance reading
The push is given by Archimedes' law
B = ρ_water g V
B = W- W_scale
B = m g - m_scale g
Let's calculate
B = 14.7 9.8 - 13.4 9.8
B = 12.74 N
ρ_water g V = 12.74
V = 12.74 / ρ_water g
V = 12.74 / 1000 9.8
V = 0.0013 m³
Let's use density
ρ = m / V
We replace
ρ = 14.7 / 0.0013
ρ = 1.13 10⁴ km/m³
Air pollution level is higher in Location B, because poisonous fumes are produced when coal burns.
C
Because in my opinion they do bending of a light wave as it passes at an angle from one medium to another.
Answer:
s = 3 m
Explanation:
Let t be the time the accelerating car starts.
Let's assume the vehicles are point masses so that "passing" takes no time.
the position of the constant velocity and accelerating vehicles are
s = vt = 40(t + 2) cm
s = ½at² = ½(20)(t)² cm
they pass when their distance is the same
½(20)(t)² = 40(t + 2)
10t² = 40t + 80
0 = 10t² - 40t - 80
0 = t² - 4t - 8
t = (4±√(4² - 4(1)(-8))) / 2(1)
t = (4± 6.928) / 2 ignore the negative time as it has not occurred yet.
t = 5.464 s
s = 40(5.464 + 2) = 298.564 cm
300 cm when rounded to the single significant digit of the question numerals.
Via half-life equation we have:
Where the initial amount is 50 grams, half-life is 4 minutes, and time elapsed is 12 minutes. By plugging those values in we get:
There is 6.25 grams left of Ra-229 after 12 minutes.
