B) 1950-1959
Sputnik I was launched on October 4, 1957
All the radiation from stars is the result of nuclear fusion in their cores.
Answer:
C
Explanation:
Sound waves speed up noticeably when moving through a solid or liquid, because all it is is just particles colliding; and particles are way closer together with those states of matter.
The speed of light can change when moving through different substances, but this is dependent on complicated factors such as frequency, polarization, intensity, et. cetera
The important part is that it does change speed, so your answer is C.
Hope this helps!
Answer:
<h2>
36cm from the surface</h2>
Explanation:
Equation of refraction of a lens is expression according to the formula given below;
R is the radius of curvature of the convex refracting surface = 12cm
v is the image distance from the refracting surface
u is the object distance from the refracting surface
n₁ and n₂ are the refractive indices of air and the medium respectively
Given parameters
R = 12 cm
u = 
(since light incident is parallel to the axis)
n₁ = 1
n₂ = 1.5
Required
<em>focus point of the light that is incident and parallel to the central axis (v)</em>
<em />
Substituting this values into the given formula we will have;
Cross multiply
Hence Light incident parallel to the central axis is focused at a point 36cm from the surface
Answer:
Contraction of Chicago concrete walkway = 8.64 x 10⁻³ m
Explanation:
Thermal expansion or compression is given by ΔL = LαΔT
Here Length of Chicago concrete walkway, L = 18 m
Change in temperature, ΔT = (-16 - 24) = -40 °C
Coefficient of thermal expansion for concrete, α = 12 x 10⁻⁶ °C⁻¹
Substituting
ΔL = LαΔT = 18 x 12 x 10⁻⁶ x (-40) = -8.64 x 10⁻³ m
Contraction of Chicago concrete walkway = 8.64 x 10⁻³ m
