(a)
we are given
The average distance from the sun to the planet Venus is about 261,000,000 km
we have to write in scientific form
In scientific form , we write expression in terms of exponent of 10
so, we can write as
[tex]261,000,000 km=261*100000km[/tex]
[tex]261,000,000 km=2.61*100*1000000km[/tex]
[tex]261,000,000 km=2.61*100000000km[/tex]
now, we can write in terms of exponents
[tex]261,000,000 km=2.61*10^8km[/tex]............Answer
(b)
we are given
The diameter of a human hair is about 0.0025 cm
we can write in scientific form as
[tex]0.00025cm=25*0.00001cm[/tex]
[tex]0.00025cm=2.5*10*0.00001cm[/tex]
[tex]0.00025cm=2.5*0.0001cm[/tex]
[tex]0.00025cm=2.5*10^{-4} cm[/tex]