Answer:
1) f= 8.6 GHz
2) t= 0.2 ms
Explanation:
1)
- Since microwaves are electromagnetic waves, they move at the same speed as the light in vacuum, i.e. 3*10⁸ m/s.
- There exists a fixed relationship between the frequency (f) , the wavelength (λ) and the propagation speed in any wave, as follows:
- Replacing by the givens, and solving for f, we get:
⇒ f = 8.6 Ghz (with two significative figures)
2)
- Assuming that the microwaves travel at a constant speed in a straight line (behaving like rays) , we can apply the definition of average velocity, as follows:
where v= c= speed of light in vacuum = 3*10⁸ m/s
d= distance between mountaintops = 52 km = 52*10³ m
⇒ t = 0.2 ms (with two significative figures)
Answer:
- The distance between the charges is 5,335.026 m
Explanation:
To obtain the forces between the particles, we can use Coulomb's Law in scalar form, this is, the force between the particles will be:
where k is Coulomb's constant, 
and 
are the charges and d is the distance between the charges.
Working a little the equation, we can take:
And this equation will give us the distance between the charges. Taking the values of the problem
(the force has a minus sign, as its attractive)
And this is the distance between the charges.
Gravity is the force that pulls you down.
(This is kind of a duh! question ... How do we know
which way is "down" ? We feel gravity, and we call
that the "down" direction.)
Magnetic force holds things to fridge doors.
Contact forces need to touch something in order to
exert their force.
Example: Gravity is NOT a contact force.
I don't know about "rubbing things away".
This might be a description of friction, but if so,
it's not a good one.
Buoyant force is what keeps floating things floating.
Air resistance slows things down when they move in air.
1) 4min = 4*60 sec = 240 sec
2) Distance = speed times time = 3 * 240 = 720 m
Answer:
Explanation:
Oil cannot dissolve in water because oil molecules repel water molecules
