Potential energy = mgh
So, energy gained
= mgh
= 70kg × (9.8m/s²) × 1000m
= 686000 kgm²/s²
= 686000 J
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 correct option is (A).
Explanation:
The direction of electric force is in the direction of electric field. The electric force acting on a charged particle is given by :
F = qE, q is magnitude of charge
We have, a negative test charge experiences a force to the right as a result of an electric field. It would mean that the electric field points to the left because the force on a negative charge is opposite to the direction of the field.
Explanation:
where is the centripetal acceleration of an object, and is the radius in which the object moves in a circle.
(hope this helps)