Answer:
in a vacuum
Explanation:
Electromagnetic waves are waves consisting of oscillations of electric and magnetic fields along a plane perpendicular to the direction of propagation of the wave (transverse waves)
Electromagnetic waves are the only waves being able to travel in a vacuum, since they do not need a medium to propagate.
In a vacuum, all electromagnetic waves travel at the same speed, called speed of light, whose value is:
The speed of the waves is actually reduced when they enter a medium, according to
where n is the refractive index of the medium.
Electromagnetic waves are also classified into 7 different types according to their wavelength. From shortest to longest wavelength, we have:
Gamma rays
X-rays
Ultraviolet
Visible light
Infrared
Microwaves
Radio waves
Answer:
Explanation:
Given that,
Initial speed, u = 0
Final speed, v = 40 m/s
Time, t = 2 s
We need to find the acceleration of the aircraft. We know that, acceleration is equal to the rate of change of velocity. So,
So, the acceleration of the aircraft is .
Answer:
a) θ₁ = 0.487º , b) t = 0.400 s , x = 11.73 ft
Explanation:
For this exercise let's use the projectile launch relationships.
The initial height is I = 5 ft and the final height y = 4 ft
y = y₀ + t - ½ g t²
The distance to the band is x = 40 yard (3 ft / 1 yard) = 120 ft
x = v₀ₓ t
t = x / v₀ₓ
We replace
y –y₀ = v_{oy} x / v₀ₓ - ½ g x² / v₀ₓ²
v_{oy} = v₀ sin θ
v₀ₓ = vo cos θ
y –y₀ = x tan θ - ½ g x² / v₀² cos² θ
5-4 = 120 tan θ - ½ 32 120 / (300 2 cos2 θ)
1 = 120 tan θ - 0.0213 sec² θ
Let's use the trigonometry relationship
Sec² θ = 1 - tan² θ
1 = 120 tan θ - 0.0213 (1 –tan²θ)
0.0213 tan²θ + 120 tanθ -1.0213 = 0
We change variables
u = tan θ
u² + 5633.8 u - 48.03 = 0
We solve the second degree equation
u = [-5633.8 ±√(5633.8 2 + 4 48.03)] / 2
u = [- 5633.8 ± 5633.82] / 2
u₁ = 0.0085
u₂= -5633.81
u = tan θ
θ = tan⁻¹ u
For u₁
θ₁ = tan⁻¹ 0.0085
θ₁ = 0.487º
For u₂
θ₂ = -89.99º
The launch angle must be 0.487º
b) let's look for the time it takes for the arrow to arrive
x = v₀ₓ t
t = x / v₀ cos θ
t = 120 / (300 cos 0.487)
t = 0.400 s
The deer must be at a distance of
v = 20 mph (5280 ft / 1 mi) (1 h / 3600s) = 29.33 ft / s
x = v t
x = 29.33 0.4
x = 11.73 ft