All electromagnetic waves travel in vacuum (space) at the speed of light (3 * 10^8 m/s). Radio waves is just a member of the electromagnetic spectrum. All electromagnetic waves follow the wave equation: speed = frequency * wavelength. With all electromagnetic waves, the speed in space is the same.
Answer:
a) 
b)
c) 
d) Treat the humans as though they were points or uniform-density spheres.
Explanation:
Given:
- mass of Mars,

- radius of the Mars,

- mass of human,

a)
Gravitation force exerted by the Mars on the human body:

where:
= gravitational constant


b)
The magnitude of the gravitational force exerted by the human on Mars is equal to the force by the Mars on human.


c)
When a similar person of the same mass is standing at a distance of 4 meters:


d)
The gravitational constant is a universal value and it remains constant in the Universe and does not depends on the size of the mass.
- Yes, we have to treat Mars as spherically symmetric so that its center of mass is at its geometric center.
- Yes, we also have to ignore the effect of sun, but as asked in the question we have to calculate the gravitational force only due to one body on another specific body which does not brings sun into picture of the consideration.
Answer:
Explain step by step
Explanation:
Collisions with asteroids, comets and other stuff from space have been responsible for huge landmarks in our planet’s history: global shifts in climate, the creation of our moon, the reshuffling of our deepest geology, and the extinction of species.
Asteroid threats pop up in the news every now and then, but the buzz tends to fizzle away as the projectiles pass us by. Other times, as with the 2013 Chelyabinsk meteor in Russia, we don’t know they’re here until they’re here.
Perhaps most useful to remember is that when near-Earth objects (including asteroids, comets and meteoroids) enter the atmosphere, they’re called meteors; and if there’s anything left when they hit the ground, the resulting object is called a meteorite. We tend to focus on asteroids when talking about potential collisions, because they’re more likely to hit us than other stuff like comets, but still big enough to pose a threat.
D=at²
441m=(5*9.81m/s²)(t²)
t²=441/(5*9.81)
t≈√8.99
t≈3 sec