d =2.55.68m and t = 11.36s
In my opinion
On Earth, gravity adds 9.8 m/s to the downwsrd speed of any falling object, every second. Beginning from zero downward speed, the speed grows to (8 x 9.8) = 78.4 m/s downward after 8 sec.
Answer: Electric current
Explanation :
The direction of the magnetic field produced by an electric current will change when the direction of the electric current changes.
For example :
If a current is flowing in a straight length of wire, the magnetic field is described by a concentric circle (using right-hand rule).
Let the field lines are in the clockwise direction and when the direction of current is reversed then the direction of the magnetic field is in anticlockwise direction.
Radiocarbon saying assume the half life for radioistopes change over time. The half life of C -14 is 5730 years
