Answer:
Explanation:
The speed of light in these mediums shall be lower than that in vacuum thus the total time light needs to cross both the media are calculated as under
Total time = Time taken through ice + Time taken through quartz
Time taken through ice = Thickness of ice / (speed of light in ice)
Thus in the same time the it would had covered a distance of
![Distance_{vaccum}=Totaltime\times V_{vaccum}\\\\Distance_{vaccum}=10^{-2}[2.20\mu _{ice+1.50\mu _{quartz}}]](https://tex.z-dn.net/?f=Distance_%7Bvaccum%7D%3DTotaltime%5Ctimes%20V_%7Bvaccum%7D%5C%5C%5C%5CDistance_%7Bvaccum%7D%3D10%5E%7B-2%7D%5B2.20%5Cmu%20_%7Bice%2B1.50%5Cmu%20_%7Bquartz%7D%7D%5D)
we have
Applying values we have
![Distance_{vaccum}=10^{-2}[2.20\times 1.309+1.50\times 1.542]](https://tex.z-dn.net/?f=Distance_%7Bvaccum%7D%3D10%5E%7B-2%7D%5B2.20%5Ctimes%201.309%2B1.50%5Ctimes%201.542%5D)
Answer:
the time needed for her to close the door is 1.36 s.
Explanation:
given information:
Force, F = 220 N
width, r = 1.40 m
weight, W = 790 N
height, h = 3.00 m
angle, θ = 90° = π/2
to find the times needed to close the door we can use the following equation
θ = ω₀t + 1/2 αt²
where
θ = angle
ω = angular velocity
α = angular acceleration
t = time
in this case, the angular velocity is zero. thus,
θ = 1/2 αt²
now, we can find the angular speed by using the torque formula
τ = I α
where
τ = torque
I = Inertia
we know that
τ = F r
and
I = 1/3 mr²
so,
τ = I α
F r = 1/3 mr² α
α = 3 F/mr
= 3 F/(w/g)r
= 3 (220)/(790/9.8) 1.4
= 5.85 rad/s²
θ = 1/2 αt²
π/2 = 1/2 5.85 t²
t = 1.36 s
To solve this problem we will apply the concepts related to the balance of Forces, the centripetal Force and Newton's second law.
I will also attach a free body diagram that allows a better understanding of the problem.
For there to be a balance between weight and normal strength, these two must be equivalent to the centripetal Force, therefore
Here,
m = Net mass
= Angular velocity
r = Radius
W = Weight
N = Normal Force
The net mass is equivalent to
Then,
Replacing we have then,
Solving to find the angular velocity we have,
Therefore the angular velocity is 0.309rad/s
B. At the equator
Explanation:
The energy coming from the Sun hits the Earth's surface at different angles, depending on the latitude of the place. The more perpendicular the ray of lights hit the surface, the more the energy transmitted to the Earth's surface, the warmer the location.
The angle at which the ray of lights hit the Earth is related to the latitude: in particular, the ray of lights arrive perpendicular at the equator (
), they arrive at larger angle in the United States (which is located at intermediate latitudes) and they arrive at the largest angles at the poles. For this reason, the sun's most energy is concentrated at the equator.
Answer:
<h2>170km</h2>
Explanation:
If a ship sets out to sail to a point 154 km due north and an unexpected storm blows the ship to a point 72 km due east of its starting point, then the ships distance from the original destination can be gotten by finding the displacement of the ship and this can be gotten by using pythagoras theorem.
Let D be the unknown displacement
According to the theorem;
D² = 154² + 72²
D² = 23716 + 5184
D² = 28900
D = √28900
D = 170km
<em>This means that the ship must now sail a distance of 170km for it to reach its original destination.</em>
