Natural sources of light include our sun and other stars, where the source of energy is nuclear energy (recall that the moon does not produce light but merely reflects sunlight), lightning, where the source is electrical, and fire, where the energy source is chemical.
It can be both flat or it can be when you have new eyeglasses on and you look down it makes you think the ground looks like that but its not
Answer:
Part a)

Part b)

Explanation:
Part a)
If block is sliding up then net force must be zero and friction will be in opposite to the direction of motion of the block


so we have





Part b)
If block is sliding down then net force must be zero and friction will be in opposite to the direction of motion of the block


so we have





Answer:
Defined below
Explanation:
Climate change is simply the long term change in the average weather patterns that are associated with the local, regional and global climates of the earth. Climate change is usually driven by human activities like burning of fossils; natural processes like cyclic ocean patterns; external factors like volcanic eruptions.
Answer:
A. 
B. 
C. ΔK
Explanation:
From the exercise we know that the car and the truck are traveling eastward. I'm going to name the car 1 and the truck 2

A. Since the two vehicles become entangled the final mass is:

From linear momentum we got that:




B. The change in velocity of both vehicles are:
For the car

For the truck

C. The change in kinetic energy is:
ΔK=
ΔK=
ΔK