Answer: Use less water
only turn on lights when needed
electrical cars
less gas usage
Explanation:
I believe the percentage is between 15-20%. Stress is a well known factor that affects the performance of people.
Answer:
The farther star will appear 4 times fainter than the star that is near to the observer.
Explanation:
Since it is given that the luminosity of the 2 stars is same thus they radiate the same energy per unit time
Consider a spherical wave front of energy 'E' that leaves both the stars (Both radiate 'E' as they have same luminosity)
This Energy is spread over the whole surface area of sphere Thus when the wave front is at a distance 'r' the energy per unit surface area is given by

For the star that is twice away from the earth the distance is '2r' thus we will receive an energy given by
Hence we sense it as 4 times fainter than the nearer star.
Answer:
A conservative force is a force with the property that the total work done in moving a particle between two points is independent of the path taken Equivalently if a particle travels in a closed loop the total work done by a conservative force is zero
Explanation: