Answer:
11.306 nm/s
or
113.06 atomic layers/sec
Explanation:
Hello!
First we need to know how much an inch equals in nanometers and a day in seconds:
Since <em>1inch = 2.54cm</em> and <em>1cm=10^7nm</em>
<em> </em>1 inch = 2.54 * 10^7 nm<em> </em>
<em />
Also <em>1day = 24hours = 24*60minutes = 24*60*60seconds</em>
<em> </em>1 day = 86.4 * 10^3 s
Therefore the rate at which the hair grows in nanometers per seconds is:
1/26 in/day = (1/26) * (2.54*10^7)/(86.4*10^3) = 11.306 nm/s
Now, if 1 atomic layer = 0.1 nm this means that 1 nm = 10 atomic layers.
Therefore:
The rate in atomic layers is
11.306 nm/s = 11.306 (10 atomic layers)/s = 113.06 atomic layers/sec
<em />
Answer:
A
Explanation:
You have to give energy away for B. You have to think about that carefully. The CO2 starts out with a great deal of energy (mostly KE) and has to slow down to go from gas to a solid. Not B
In general C is the same way. Water has more energy than ice. Not C
Same principle in D. Not D.
So it's A
Answer:
c. Both forces have equal magnitudes.
Explanation:
According to Newton´s 3rd Law, the force exerted by a body on another one , is equal and opposite to the one that the second object exerts on the first one.
This does not depend on the masses of the objects, so it doesn´t matter that m₁ be greater than m₂.
As examples of this, we can mention the gravity force, the electrostatic force, the normal force, etc.
So, in this case, taking into account only the magnitudes, we can say:
F₁₂ = F₂₁
Answer:
M = 0.31 kg
Explanation:
This exercise must be done in parts, let's start by finding the speed of the set arrow plus apple, for this we define a system formed by the arrow and the apple, therefore the forces during the collision are internal and the moment is conserved
let's use m for the mass of the arrow with velocity v₁ = 20.4 m / s and M for the mass of the apple
initial instant. Just before the crash
p₀ = m v₁ + M 0
instant fianl. Right after the crash
p_f = (m + M) v
p₀ = p_f
m v₁ = (m + M) v
v = (1)
now we can work the arrow plus apple set when it leaves the child's head with horizontal speed and reaches the floor at x = 8 m. We can use kinematics to find the velocity of the set
x = v t
y = y₀ + t - ½ g t²
when it reaches the ground, its height is y = 0 and as it comes out horizontally,
0 = h - ½ g t²
t² = 2h / g
For the solution of the exercise, the height of the child must be known, suppose that h = 1 m
t =
t = 0.452 s
let's find the initial velocity
v = v / t
v = 8 / 0.452
v = 17.7 m / s
From equation 1
v = m / (m + M) v₁
m + M =
M = m + m \ \frac{v_1}{v}
we calculate
M = 0.144 + 0.144
M = 0.31 kg