A
More concentrated means more collisions per unit volume, and as the volume stays the same and only concentration changes, the there are more collisions
B) Not work since decrease in temperature wouldnt cause evaporation or reverse in cycle.
Answer:
The work done by gravity is 
Explanation:
The data given in the question is :
Mass is 
Height from ground is 
As we know , the work done is state function , it depends on initial and final position not on the path followed.
So, work done by gravity = change in potential energy
Work done = Initial potential energy - final potential energy
Insert values from question
Work done = 
Work done = 
So, work done = 
Hence the work done by gravity is
Explanation:
We want to find the statement that is proven by the fact that the balls reach the same height.
A isn't supported by the evidence. Balls can reach the same height without having the same initial speed.
B isn't supported by the evidence. Balls can reach the same height without having the same launch angle.
C is supported. Projectiles spend the same amount of time going up as they do coming down, so if two projectiles reach the same height, then they must spend the same amount of time in the air.
D isn't supported by the evidence. Balls thrown at the same speed and complementary angles have the same range but different heights.
E isn't supported by the evidence. The mass of the ball doesn't affect the height.
