Answer :
- Time=1s=t
- Acceleration due to gravity=g=9.8m/s^2
- Distance=s
In free fall
[tex]\boxed{\sf s=-\dfrac{1}{2}gt^2}[/tex]
[tex]\\ \sf\longmapsto s=-\dfrac{1}{2}\times 9.8(1)^2[/tex]
[tex]\\ \sf\longmapsto s=-4.9(1)[/tex]
[tex]\\ \sf\longmapsto s=-4.9m[/tex]
- Take it positive
[tex]\\ \sf\longmapsto s=4.9m[/tex]
- Option a is correct