Answer:
height = 45 m
Explanation:
Initial velocity = 0 m/s
Final velocity = 30 m/s
Acceleration due to gravity = +10m/s^2 ( because ball is going down )
Using the eqn of motion
where v= final velocity ; u = initial velocity ; g = acceleration due to gravity ; h = height
So,
The sun is bright and when its cold there is no sun
The answer is either
b A system in which Newton's Laws are valid
or
c A system in which there are no external forces.
Explanation:
not a, and not d
There are energy changes in a closed system.
A closed system obeys the conservation laws in its physical description.
Their Period number is common means their "Principal Quantum Numbers" are same
Hope this helps!
