Answer:
A?
Explanation:
i don't know correct me if i'm wrong
what is the energy of a photon with a wavelength of 21 nm? hint: treat the planck constant as 7 x 10-34 j*s
The energy of a photon with a wavelength of 21 nm is approximately 9.429 x [tex]10^-^1^6[/tex] Joules.
The energy of a photon can be calculated using Planck's equation:
E = (hc) / λ
Where:
E is the energy of the photon,h is the Planck constant (7 x [tex]10^-^3^4[/tex] Joule-second),c is the speed of light (3.00 x [tex]10^8[/tex] m/s),λ is the wavelength of the photon.Given that the wavelength (λ) is 21 nm (21 x [tex]10^-^9[/tex] m) and using the given value of the Planck constant, we can calculate the energy of the photon:
E = (7 x [tex]10^-^3^4[/tex] x 3.00 x 10^8) / (21 x[tex]10^-^9[/tex] )
When we calculate this, we get the value: 9.429 x [tex]10^-^1^6[/tex] Joules.
Therefore, the energy of a photon with a wavelength of 21 nm is approximately 9.429 x [tex]10^-^1^6[/tex] Joules.
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An object accelerates from rest at a constant rate of 4ms-² for a distance 200m. How fast is the object moving at that time? How long did take for the object to reach that velocity?
Answer:
it moves with a speed of 20m/s and for 10 seconds
Explanation:
using Newton's third law of motion ....s=ut +at/2 ....where s is the distance covered....t time taken ;can be found and since the object was at rest the u ....initial velocity will be 0
The object moves with a speed of 20m/s for time 10 sec.
Explain Newton's third law of motion?According to Newton's third law, there is an equal and opposite reaction to every force (action) in nature. When object A pulls on item B, object B pulls back on object A with an equal and opposing force. In other words, interactions lead to forces. The air is diverted downward by an airfoil's action, and the wing is pushed upward as a result. This is the motion of lift from an airfoil.
When a ball is spinning, the air deflects to one side, causing the ball to move in the opposite direction as a response.
When a jet engine is moving, thrust is produced, hot exhaust gases exit the back of the engine, and thrust is generated in the opposite direction.
Using Newton's third law of motion,
where,
s is the distance covered
t time taken ;can be found and since the object was at rest the
u initial velocity will be 0
S = v₀t + [tex]\frac{1}{2}[/tex]at²
S = 0⋅t + [tex]\frac{1}{2}[/tex] ⋅ at²
S = [tex]\frac{1}{2}[/tex] ⋅ at²
t² = [tex]\frac{2s}{a}[/tex]
t² = [tex]\frac{2(200)}{4}[/tex]
t² = 100
t = 10 sec.
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object 1 has an irregular shape. its density is 4000 kg/m3 . part a part complete object 2 has the same shape and dimensions as object 1, but it is twice as massive. what is the density of object 2? express your answer in kilograms per cubic meter. rho2
The density of object 2 is 8000kg/m^3.
d=2d=8000kg/m^3
What is density?The substance's density is defined as its mass per unit of volume (volumetric mass density or specific mass). Although the Latin letter D may also be used, the symbol for density that is most usually used is (the lower case Greek letter rho). Mathematically, density is determined by dividing mass by volume.
Weight per unit volume is a common informal definition of density, although this is incorrect scientifically; the exact term is specific weight. The US oil and gas industry serves as one illustration of this.A pure substance's mass concentration in numbers is equal to its density. Density varies greatly between different types of materials and may be significant in terms of packaging, purity, and buoyancy.
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an earthquake 45 km from a city produces p and s waves that ravel outward at 5000 and 3000 m/s, respectively. once city residents feel the shaking of the p wave, how much time do they have before the s wave arrives?
By the velocity, the interval time after the p wave arrived is 6 seconds.
We need to know about velocity to solve this problem. Velocity can be determined as the distance traveled divided by time interval. It can be written as
v = s / t
where v is velocity, s is distance and t is the time interval.
From the question above, we know that.
vp = 5000 m/s
vs = 3000 m/s
s = 45 km = 45000 m
Determine the time taken by p wave
tp = s / vp
tp = 45000 / 5000
tp = 9 seconds
Determine the time taken by s wave
ts = s / vs
ts = 45000 / 3000
ts = 15 seconds
The time interval after p waves is
interval time = ts - tp
interval time = 15 - 9
interval time = 6 second
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