Answer:
A-Light from the Sun reflects off the Moon as it orbits Earth
Answer:
D
Explanation:
light moves in a straight line (sorry if I'm wrong)
Answer:
The concentration downstream reduces to 0.03463mg/L
Explanation:
Initially let us calculate the time it is required to fill the lake, since for that period of time the pollutant shall remain in the lake before being flushed out.
Thus the detention period is calculated as

Now the concentration of the pollutant after 14.872 days is calculated as

where
is the initial concentration
't' is the time elapsed after which the remaining concentration is calculated
k is the dissociation constant.
Applying values we get


Answer:
t = 5.56 s
Explanation:
In order to calculate the time interval taken by the mountain biker to come to a stop, we will use third equation of motion and first find the deceleration:
2as = Vf² - Vi²
where,
a = deceleration = ?
s = distance = 15 m
Vf = Final Velocity = 0 m/s
Vi = Initial Velocity = 5.4 m/s
Therefore,
2a(15 m) = (0 m/s²) - (5.4 m/s)²
a = - 0.972 m/s²
Now, we use 1st equation of motion:
Vf = Vi + at
therefore,
0 m/s = 5.4 m/s + (-0.972 m/s²)(t)
t = (5.4 m/s)/(0.972 m/s²)
<u>t = 5.56 s</u>