Answer:
E = h f = h c / λ energy of single photon
n E = 4.00E-11 W/m^2 energy required for visibility
n h c / λ = 4.00E-11 number of photons required for visibility (per square meter)
n = 4.00E-11 * 5.00E-7 / (6.63E-34 * 3.00E8)
n = 20.0E-18 / 19.9 E-26 = 1.00E8
100 million photons would be required on 1 m^2 to create visibility
a / A = π * (3.6E-3)^2 / 1 = 4.07E-5 fraction of area available
4.07E-5 * 1.00E8 = 4.07E3 photons required
- initial velocity=15m/s=u
- Acceleration=a=5m/s^2
- Final velocity=v=30m/s
- Distance be s
Using 3rd equation of kinematics
Answer:
a) V ≈ 125 m/s; b) Δt = 13.24 s; c) ΔS ≈ 1450 m
Explanation:
a) We have just to calculate the vector resultant.
V² = 106² + 66.2²
V² = 15618.44
V ≈ 125 m/s
b) The time of flight is equal to the time to reach the maximum height summed to the time to reach the land.
In vertical:
V = V₀ + a * t
V = 66.2 - g * t
0 = 66.2 - 9.8 * t
t ≈ 6.76 s
So: Δt = 13.24 s
c) In horizontal:
V = ΔS / Δt
106 = ΔS / 13.52 ⇒ ΔS = 106 * 13.52
ΔS = 106 * 13.52
ΔS = 1433,12
ΔS ≈ 1450 m
Answer:
A
Explanation:
The abundance of oxygen in our atmosphere and the presence of liquid water on the surface of our planet makes our "Pale Blue Dot" stand out in contrast to the other planets in the solar system — a unique and fragile home for life.
Answer:
Few millimeter thick aluminium, water, wood, acrylic glass or plastic.
Explanation:
The materials that are best for protection against beta particles are few millimeter thickness of aluminium, but for the high energy beta-particles radiations the low atomic mass materials such as plastic, wood, water and acrylic glass can be used.
These materials can also be used in personal protective equipment which includes all the clothing that can be worn to prevent any injury or illness due to the exposure to radiation.
