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:F=4F
Explanation: Columbs law states that The force between the two point charges is directly proportional to the product of charges and inversely proportional to the square of distance between them
Force between the two charges is given by
F=K*q1*q2/r^2
if one charge become 4 times, new force is,
F=4(K*q1*q2)/r^2
F=4F
Where q1 and q2 are the point charges
r is the distance between the two charges
K is a constant of proportion called electrostatic force
Answer:
sample. rewrite in your own words if you'd like.
Explanation:
Since the hydrangeas are changing color depending on whether the soil is acidic or basic, they must have an indicator. This means that any hydrangea planted in acidic soil will have blue flowers and any hydrangea planted in basic soil will have pink. One common indicator present in many plants is anthocyanin, so maybe hydrangeas contain that chemical.
To reduce friction between two surfaces, you have to
make the surfaces smoother.
The best way to do that is to introduce a fluid between them,
like grease, oil, or air.
