Cause he left out the noble gases out of the periodic table for one good reason, 1: He did not know them
That waves travel faster than the wave lenght!
The drop in physical activity is partly due to inaction during leisure time and sedentary behaviour on the job and at home. Likewise, an increase in the use of "passive" modes of transportation also contributes to insufficient physical activity.
We know, Potential Energy = m * g * h
Here, mass & gravity would be same, but their height will change so it will be:
ΔU = U₂ - U₁
ΔU = mgh₂ - mgh₁
ΔU = mg (h₂ - h₁)
Hope this helps!
Answer:
Instantaneous speed means speed at any instant
that means Speed is changing with time
You know speed is distance/time
So that means distance is also changing with time
So we take infinitesimal small distance per infinitesimal small time As we assume speed is constant in infinitesimal small time dt
So, we take speed = ds/dt
ds = infinitesimal small distance
dt = infinitesimal small time
As its ratio is equal to speed at any instant
Note : We are taking infinitesimal small distance
But :) we are taking infinitesimal small time also
As you know if denominator is small fraction is large So fraction always give large value
So it's not O ( this makes confuse to most of students)
So, thanks
Good question
Keep thinking like this :)