Answer:
The observer detects light of wavelength is 115 nm.
(b) is correct option
Explanation:
Given that,
Wavelength of source = 500 nm
Velocity = 0.90 c
We need to calculate the wavelength of observer
Using Doppler effect

Where, 


Hence, The observer detects light of wavelength is 115 nm.
Answer:
100
Explanation:
by dividing 2000N and 1000kg.
If the temperature is high there is less water because it evaporates if it is cloudy it is more because it doesn't evaporate
Answer:
(a) 3.807 s
(b) 145.581 m
Explanation:
Let Δt = t2 - t1 be the time it takes from the moment when the motorcycle starts to accelerate until it catches up with the car. We know that before the acceleration, both vehicles are travelling at a constant speed. So they would maintain a distance of 58 m prior to the acceleration.
The distance traveled by car after Δt (seconds) at
speed is

The distance traveled by the motorcycle after Δt (seconds) at
speed and acceleration of a = 8 m/s2 is


We know that the motorcycle catches up to the car after Δt, so it must have covered the distance that the car travels, plus their initial distance:





(b)


Answer: Hello!
Lewis is travelling at 165 mph, which means miles per hour, this says that he does 165 miles in one hour.
We want to know how much time takes to cover 16 miles.
this can be calculated as the quotient of the distance and the velocity; this is:

if we want to write this in minutes, then:
we know that one hour has 60 minutes, then 0.096 hours has:
0.096h*60mins/1h = 5.8 minutes.
then Lewis needs 5.8 minutes in order to cover 16 miles if his speed is 156 miles per hour.