Melting, as igneous rock is magma or lava that has cooled and hardened.
Answer:
Explanation:
Speed of skier without parachute
= √ 2gh
= √ 2 x 9.8 x 35
= 26.2 m / s
Speed of skier with parachute
net force downwards
mg - 200
= 60 x 9.8 -200
= 388 N
acceleration = 388 / 60
a = 6.47 m / s
v = √ 2ah
= √ 2 x 6.47 x 35
= 21.28 m / s
206Pb = 1.342 x10^22 atoms
<span>To find the number of atoms, you must first find the number of moles. If 238U is 238.029g/mol, and we have 1.75 grams, how many moles is that? 1.75 divided by 238.029 = 0.007352045 moles. To find the number of atoms in 0.007352045 moles, you multiply by a mole: </span>
<span>0.007352045 x 6.02 x 10^23 = 4.426 x10^21 atoms. </span>
<span>Same procedure for 206Pb: </span>
<span>4.59 divided by 205.97446 = 0.022284316 moles </span>
<span>0.022284316 x 6.02 x 10^23 = 1.342 x10^22 atoms. </span>
<span>Hope that helps you!
https://answers.yahoo.com/question/index?qid=20100331153014AAoMXcu
</span>
Answer:
Explanation:
The formula for this, the easy one, is
where No is the initial amount of the element, t is the time in years, and H is the half life. Filling in:
and simplifying a bit:
and
N = 48.0(.0625) so
N = 3 mg left after 12.3 years
Answer:
The correct answer is B
Explanation:
To calculate the acceleration we must use Newton's second law
F = m a
a = F / m
To calculate the force we use the defined pressure and the radiation pressure for an absorbent surface
P = I / c absorbent surface
P = F / A
F / A = I / c
F = I A / c
The area of area of a circle is
A = π r²
We replace
F = I π r² / c
Let's calculate
F = 8.0 10⁻³ π (1.0 10⁻⁶)²/3 10⁸
F = 8.375 10⁻²³ N
Density is
ρ = m / V
m = ρ V
m = ρ (4/3 π r³)
m = 4500 (4/3 π (1 10⁻⁶)³)
m = 1,885 10⁻¹⁴ kg
Let's calculate the acceleration
a = 8.375 10⁻²³ / 1.885 10⁻¹⁴
a = 4.44 10⁻⁹ m/s² absorbent surface
The correct answer is B
