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:
Maybe
Explanation:
It depends. If he says the shoes sucked than no because they suck-
But if he really liked the shoes and said it was really good than yes
I would buy the shoes
Assume that energy losses (due to aerodynamic resistance or bearing friction are negligible).
At the highest point, the pendulum has its maximum potential energy (PE) and zero kinetic energy (KE). The total energy is equal to the PE = 141 J.
At the lowest point, the pendulum has its maximum KE, and zero PE. The total energy is equal to the KE.
Because energy is preserved, therefore
KE at the lowest point = PE at the highest point = 141 J.
Answer: 141 J
Answer:

Explanation:
Given data
Speed v=2650 km/h
Radius r=85.0 km
To find
Centripetal Acceleration
Solution
As centripetal acceleration is given as

where
v is velocity
r is the radius
Substitute the given values in eq(i)

Answer:
Gwen’s assumption of asteroid hit as long term change is incorrect. Asteroid hit is not a long term change, instead, it is a short term change.
Explanation:
Examples of short term changes are drought, flood, volcanic eruption, etc. A short term change occurs quickly and can immediately affect organisms but it doesn’t become a reason for species extinction. The effects of a short term change don’t prevail over a long span of time.
Examples of long term changes are ice age, global warming, deforestation, etc. Unlike a short term change, it takes time but the consequences are far-reaching. It can lead to species extinction.
In this question, asteroid hit is a quick and unexpected hazard, unlike the slow long term environmental changes.