Answer:
I think they use it at night because they want to avoid involving themselves in road accident while crossing the street. When there are reflective strips on their clothes, drivers do notice them even at far ends of the street since the strips will reflect the rays from the car lights to the driver,hence, the driver notifies that there is a pedestrian crossing and therefore slows down.
Answer:
F_A = 8 F_B
Explanation:
The force exerted by the planet on each moon is given by the law of universal gravitation
F = 
where M is the mass of the planet, m the mass of the moon and r the distance between its centers
let's apply this equation to our case
Moon A
the distance between the planet and the moon A is r and the mass of the moon is 2m
F_A = G \frac{2m M}{r^{2} }
Moon B
F_B = G \frac{m M}{(2r)^{2} }
F_B = G \frac{m M}{4 r^{2} }
the relationship between these forces is
F_B / F_A =
= 1/8
F_A = 8 F_B
Answer:
Please see below as the answer is self-explanatory.
Explanation:
- The visible range extends roughly from 400 nm (violet) to 700 nm (red).
- Below the violet is the ultra-violet spectrum (with higher energy) and above red, we have the infra-red spectrum.
- The wavelengths in the range of 650 to 690 nm have red as the dominant color.