Answer:
E = 4.7 x [tex]10^{-19}[/tex] Joules
Explanation:
Solution:
The wavelength of a particular color of violet light = 417 nm
What is the energy = ?
In order to calculate energy, we will use the following formula:
E = hf
where, f = frequency = 1/wavelength = c/λ
where c = speed of light = 299 792 458 m / s or 3 x [tex]10^{8}[/tex] m/s
where h = Plank's constant = 6.62x [tex]10^{-34}[/tex] [tex]m^{2}[/tex] kg / s
So,
λ = 417 nm
1 nm = [tex]10^{-9}[/tex] m
so,
λ = 417 x [tex]10^{-9}[/tex] m
Now, just plug in the values to calculate the energy of this wavelength of light.
E = hc/λ
E = ( 6.62x [tex]10^{-34}[/tex] ) (299 792 458) / (417 x [tex]10^{-9}[/tex] )
E = 0.047 x[tex]10^{-17}[/tex]
E = 4.7 x [tex]10^{-19}[/tex] Joules
A bullet has a mass of 0.06 kg. Starting from rest, after the gun's trigger is pulled, a constant force acts on the bullet for the next 0.025 seconds until the bullet leaves the barrel of the gun with a speed of 992 m/s.
What is the change in momentum of the bullet?
The change in momentum of the bullet : 59.52 kg m/s
Further explanationGiven
m=0.06 kg
Δt=0.025 s
vo=0(from rest)
vt= 992 m/s
Required
The change in momentum
Solution
The change in momentum = ΔP
ΔP =m(vt-vo)
ΔP =0.06(992-0)
ΔP =59.52 kg m/s
A block of mass m is hung from the ceiling by the system of massless springs consisting of two layers. The upper layer consists of 3 strings in paralle, and the lower layer consists of 2 strings in parallel. The horizontal bar between the two layers has negligible mass. The force constants of all springs are k. Calculate the period of the vertical oscillations of the block.
Answer:
T₀ = 2π [tex]\sqrt{\frac{m}{k} }[/tex] T = [tex]\sqrt{\frac{5}{6} }[/tex] T₀
Explanation:
When the block is oscillating it forms a simple harmonic motion, which in the case of a spring and a mass has an angular velocity
w = [tex]\sqrt{k/m}[/tex]
To apply this formula to our case, let's look for the equivalent constant of the springs.
Let's start with the springs in parallels.
* the three springs in the upper part, when stretched, lengthen the same distance, therefore the total force is
F_total = F₁ + F₂ + F₃
the springs fulfill Hooke's law and indicate that the spring constant is the same for all three,
F_total = - k x - k x - kx = -3k x
therefore the equivalent constant for the combination of the springs at the top is
k₁ = 3 k
* the two springs at the bottom
following the same reasoning the force at the bottom is
F_total2 = - 2 k x
the equivalent constant at the bottom is
k₂ = 2 k
now let's work the two springs are equivalent that are in series
the top spring is stretched by an amount x₁ and the bottom spring is stretched x₂
x₂ = x -x₁
x₂ + x₁ = x
if we consider that the springs have no masses we can use Hooke's law
[tex]-\frac{F_{1} }{k_{1} } - \frac{F_{2}}{k_{2} } = \frac{F}{k_{eq} }[/tex]
therefore the equivalent constant is the series combination is
[tex]\frac{1}{k_{eq} } = \frac{1}{k_{1} } + \frac{1}{k_{2} }[/tex]
we substitute the values
\frac{1}{k_{eq} } = \frac{1}{3k } + \frac{1}{2k }
\frac{1}{k_{eq} } = \frac{5}{6k} }
k_eq = [tex]\frac{6k}{5}[/tex]
therefore the angular velocity is
w = [tex]\sqrt{\frac{6k}{5m} }[/tex]
angular velocity, frequency, and period are related
w = 2π f = 2π / T
T = 2π / w
T = 2π [tex]\sqrt{\frac{5m}{6k} }[/tex]
T₀ = 2π [tex]\sqrt{\frac{m}{k} }[/tex]
T = [tex]\sqrt{\frac{5}{6} }[/tex] T₀
Which of these is another name for Newton's
first law?
A. the law of action-reaction
B. the law of force and acceleration
C. the law of gravity
D. the law of inertia
a string attached to a 60.0 Hz vibr.ator creates a standing wave with 5 loops. What frequency would make 7 loops? (Unit = Hz)
Answer:
F=84.0 Hz
Explanation:
Using the equation f= n (v/2L), frequency equals number of loops times velocity over 2 times the length, in order to get 60.0 Hz of frequency from 5 loops, v/2L would have to equal 12. (12*5=60) v/2L is constant, so to find the frequency of 7 loops you would times 7 by 12 to get 84.0.
Hope this helped! :)
5) Choose the best revision of the following statement: "All the isotopes of a particular element decay radioactively by
emitting electrons."
A. All the isotopes of a particular element are stable and do not decay.
B. Some isotopes are stable and others are unstable. Unstable isotopes decay by emitting various subatomic
particles and radiation
C. Some isotopes are stable and others are unstable. Unstable isotopes decay by emitting protons or
electrons.
D. The statement is correct as it is currently written.
Answer:
B. some isotopes are stable and others are unstable. unstable isotopes decay by emitting various subatomic particles and radiation.
Explanation:
test gave me the answer so yeah :/ XD
which is true about the way air flows
A. high pressure to low pressure
B. low pressure to high pressure
C. cold air to hot air
D. hot air to cold air
Answer:
A High-to-Low
Explanation:
its like water running down a hill.
1. Determine the kinetic energy of a 625-kg roller coaster car that is moving with a speed of 18.3 m/s,
Answer:
104653.13J
Explanation:
Given parameters:
Mass of roller coaster = 625kg
Speed = 18.3m/s
Unknown:
Kinetic energy = ?
Solution:
The kinetic energy is the energy due to the motion of a body.
Kinetic energy = [tex]\frac{1}{2}[/tex] x m x v²
m is the mass
v is the speed
Kinetic energy = [tex]\frac{1}{2}[/tex] x 625 x 18.3² = 104653.13J
