<span>The precautions which should
be taken on board a vessel during a lightning storm are:</span>
<span>(i) </span>All
electrical equipments should be unplugged.
<span>(ii) </span>Keep
yourself away from all metal parts such as engines, metal tanks, stoves etc.
<span>(iii) </span><span>Stay inside the boat. </span>
You get circular motion, where the acceleration is pointing towards the center of the circle, as long as they are constant, and not fluctuating.
Answer:
a) y₂ = 49.1 m
, t = 1.02 s
, b) y = 49.1 m
, t= 1.02 s
Explanation:
a) We will solve this problem with the missile launch kinematic equations, to find the maximum height, at this point the vertical speed is zero
² =
² - 2 g (y –yo)
The origin of the coordinate system is on the floor and the ball is thrown from a height
y-yo =
=
- g t
t =
/ g
t = 10 / 9.8
t = 1.02 s
b) the maximum height
y- 44.0 =
² / 2 g
y - 44.0 = 5.1
y = 5.1 +44.0
y = 49.1 m
The time is the same because it does not depend on the initial height
t = 1.02 s
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:
basically they have too much mass in them
Explanation:
They are held tightly together by strong forces of attraction. They are held in fixed positions but they do vibrate. Because the particles don't move, solids have a definite shape and volume, and can't flow. Because the particles are already packed closely together, solids can't easily be compressed.