Choose the correct description of what do we mean when we say that light is an electromagnetic wave and the relationship among w
1 answer:
An electromagnetic wave is the oscillation of electric and magnetic fields that propagate in the space. Electromagnetic waves carry energy and they do not need a medium to propagate (they can travel in vacuum as well).
The correct relationship between the speed of the wave (speed of light, c), the frequency f and the wavelength
is
The correct relationship between the speed of the wave (speed of light, c), the frequency f and the wavelength
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Answer:
v = 28.98 ft / s
Explanation:
For this problem we must solve it in parts, let's start by looking for the speed of the two cars after the collision
In the exercise they indicate the weight of each car
Wₐ = 1500 lb
W_b = 1125 lb
Car B's velocity from v_b = 42.0 mph westward, car A travels east
let's find the mass of the vehicles
W = mg
m = W / g
mₐ = Wₐ / g
m_b = W_b / g
mₐ = 1500/32 = 46.875 slug
m_b = 125/32 = 35,156 slug
Let's reduce to the english system
v_b = 42.0 mph (5280 foot / 1 mile) (1h / 3600s) = 61.6 ft / s
We define a system formed by the two vehicles, so that the forces during the crash have been internal and the moment is preserved
we assume the direction to the east (right) positive
initial instant. Before the crash
p₀ = mₐ v₀ₐ - m_b v_{ob}
final instant. Right after the crash
p_f = (mₐ + m_b) v
the moment is preserved
p₀ = p_f
mₐ v₀ₐ - m_b v_{ob} = (mₐ + m_b) v
v =
we substitute the values
v =
v = 0.559 v₀ₐ - 26.40 (1)
Now as the two vehicles united we can use the relationship between work and kinetic energy
the total mass is
M = mₐ + m_b
M = 46,875 + 35,156 = 82,031 slug
starting point. Jsto after the crash
K₀ = ½ M v²
final point. When they stop
K_f = 0
The work is
W = - fr x
the negative sign is because the friction forces are always opposite to the displacement
Let's write Newton's second law
Axis y
N-W = 0
N = W
the friction force has the expression
fr = μ N
we substitute
-μ W x = Kf - Ko
-μ W x = 0 - ½ (W / g) v²
v² = 2 μ g x
v = Ra (2 0.750 32 17.5
v = 28.98 ft / s
Answer:
The height is
Explanation:
From the question we are told that
The combined mass of the child and the sled is
The speed of the sled is
Generally applying SOHCAHTOA on the slope which the combined mass is down from
Here the length of the slope(L) where the combined mass slides through is the hypotenuses
while the height(h) of the height of the slope is the opposite
Hence from SOHCAHTOA
=>
Generally from the kinematic equation we have that
Here the u is the initial velocity of the combined mass which is zero since it started from rest
and a is the acceleration of the combined mass which is mathematically evaluated as
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