The atmosphere creates a cover over the earth preventing us from seeing space and it’s natural color and the light that is created by the sun reflected on the ocean creates the color that the sky appears to be blue
Answer:
Pi(3.14) radians or 180º degrees
Explanation:
First of all, we need to obtain the wavelength of a wave traveling to the speed of sound and 420 Hz of frequency.
The formula is:

where l = wavelength in meters
With current values:
l = 336 [m/s]/420[1/s] = 0.8 meters
Since a complete cycle (360º or 2pi radians) needs 0.8 meters to complete, 0.4 meters or 40 cm is just half of it, making a 180º degree phase or 3.14 radians.
Answer:
The final position of the ship after the given time period is 42 km West of B.
Explanation:
Given;
average velocity of the ship, v = 35 km/h
time taken for the ship to reach point D, t = 1.2 hours
The position of the ship after the given time period is calculated as follows;
x = v x t
x = (35 km/h) x 1.2 h = 42 km
x = 42 km West of B.
Therefore, the final position of the ship after the given time period is 42 km West of B.
Answer:

Explanation:
When we shoot the dart upwards the time taken by the dart to go straight up and again come back is given as

here we can say


put t = 4.6 s then we have

Now in order to find the maximum range we can say

so in order to have maximum range we can say




Answer:
The total number of electrons is 
(3) is correct option.
Explanation:
Given that,
The current equation is

We know that,
The formula of charge








We need to calculate the number of electron
Using formula of charge




Hence, The total number of electrons is 