I am going to say velocity because you have the same amount of acceleration going in a certain direction.
Answer:
All are correct except the age of earth. The age of Earth is approximately 4.543 Billion Years.
Answer:
DETAILS IN THE QUESTION INSUFFICIENT TO ANSWER
Explanation:
Assuming the liquid to be water ,
the density
of water is :
Buoyant force exerted by a liquid on an object with
of it's volume immersed is :

where ,
is the buoyant force
is the density of the liquid
is the acceleration due to gravity
Thus at equilibrium:

from these , we get the density of brass to be 
which is not possible
Explanation:
for v vs t graph for t=9 to 11,v=15kmph
similarly v2=0,v3=60kmph&v4= -40kmph
3.85 pounds is the answer