Answer:
b. Plants and animals exchanging gases with the atmosphere
Explanation:
Can you post the question
Answer:
Explanation:
When we react Hydrochlorid Acid with zinc we have the following reaction:
2HCl(aq) + Zn(s) --> ZnCl2(aq) + H2(g)
The hydrogen gas formed is lost to the environment, so we can affirme that in the start we have the mass for all the H, Cl and Zn atoms in the solution, but after the reaction occurs, we have only the mass for the Cl and Zn atoms.
That's why the mass is less than the original.
The law that the student was told is only applied to closed environments.
Answer: The correct answer is option(A).
Explanation:
Total forces exerting on the car = F
= Force on car exerting in right direction
= Force on car exerting in left direction
= Force on car exerting in upward direction
= Force on car exerting in downward direction
(negative sign shows the direction)
Since, upward force are equal in magnitude but opposite in direction by which they will balance out each other.so, the net force car will be due to two forces 
and 
(negative shows the direction)
The magnitude (size) and direction of the cumulative force acting on the car will 30 N towards right direction.Hence, correct answer is option(A).
