If we consider our origin to be zero then if we walk 15m west then back 7m east our displacement would be the difference (since west and east are opposite directions to one another).
15m - 7m = 8m
And so, we are 8 meters away from our origin, thus our displacement is 8 meters.
Complete Question
A voltaic cell utilizes the following reaction and operates at 298 K:
3Ce4+(aq)+Cr(s)→3Ce3+(aq)+Cr3+(aq).
What is the emf of this cell under standard conditions? Express your answer using three significant figures.
Answer:
The value is 
Explanation:
From the question we are told that
The ionic equation is

Now under standard conditions the reduction half reaction is

And the oxidation half reaction is

The emf of this cell under standard conditions is mathematically represented as

substituting values


The student that measured the mass to be 16110g got closest to the known result. She is off by 10 g.
Answer:
Trenches are the deepest part of the oceans, narrow and long depressions on the sea floor. One good example is the Mariana Trench, the deepest part of the ocean
Explanation:
The answer is (C)= zero but that it is swirling rapidly in all directions.