<span>While
modern humans first evolved approximately 200,000 years ago,
the age of
the Earth, the Sun, and the rest of the solar system is believed
to be approximately 4.6 billion years.
That makes the Earth, the Sun, and the rest of the solar system
something like 23 thousand times as old as the human species !
</span>
Answer:
-1.09m/sec^2
Explanation:
Acceleration= (Vf-Vi)/Time
=12-54.8
= -42.8
= -42.8/39
=-1.09
-ve sign is due to recoil of train
as it suddenly hits brakes.
Time= s/v
Speed =5km/h
Time=30min
Distance is required
Distance=time*speed
30min*5km/h=600m
Displacement is a vector quantity. So, you incorporate the vector calculations when you try to determine the resultant vector. This is the shortest path from the starting point to the endpoint. If they are moving on one axis only, you use sign conventions. For motions moving to the left, use the negative sign. If it's moving to the right, then use the positive sign. Now, it the object moves 2 km to the left, and 2 km also to the right, the displacement is zero.
Displacement = 2 km - 2km = 0
Generally, the equation is:
<span>Displacement = Distance of motion to the right - Distance of motion to the left</span>
