Answer:
2 m/s
Explanation:
Velocity is a vector quantity that is given by:

where
d is the displacement of the object (a vector indicating its change in position)
t is the time elapsed
Note that since velocity is a vector, it has both a magnitude and a direction (the same as the displacement).
For the toy train in this problem, we have:
d = 40 m (displacement)
t = 20 s (time elapsed)
So, its velocity is:

Kinetic energy will go down accordingly (if no external force)
Answer:
1. Burning coal contributes to sulfur aerosols in the stratosphere; these sulfur aerosols have moderated global warming.
Explanation:
Sulfur aerosols both absorb as well as scatter solar radiation coming from the sun , thus saving the earth from getting wormed up . In this way it has moderating effect on the global warming . This is also called global dimming effect. Less of the solar radiation is able to reach earth surface due to these aerosol.
Answer:
true
Explanation:
because the bonds in that element can only be shared but not transferred , but sometimes it depends on the element