Answer:
A. Speed
Explanation:
A vector quantity is a quantity which has both magnitude and direction. Here in the given options, speed is a scalar quantity but not the vector quantity.
Answer:
Let No be initial no of atoms
N = N0 / 2 after 1 half-life
N = N0 / 4 after 2 half-lives
So after 2 half-lives 20 of the 80 atoms remain
Answer:
Air resistance/Drag (this is the proper term for air resistance) or gravity or friction
It depends on the direction and if you throw it across a surface or if you throw it straight upwards.
I hope this helps!!