To fully describe the motion of an object requires knowing each of five _______ movement: displacement, time, initial velocity, final...

Let's begin by understanding the meaning of this sentence. We'll use our understanding of pause points and segment the sentence as shown - understanding and assimilating the meaning of each segment bit by bit!

Sentence Structure

• First sentence:
  • To fully describe the motion of an object requires knowing each of five [?] movement:
    • displacement,
    • time,
    • initial velocity,
    • final velocity,
    • and acceleration.
• Second sentence:
  • These are called kinematic variables.
• Blank varies: variable's/variables + objects'/object's/objects
• Common: 'that characterize' appears in all choices

Understanding the Meaning

Let's start reading and understanding the sentence:

'To fully describe the motion of an object requires knowing each of five...'

Now we've reached the blank. Let's look at our choices to see what we're deciding:

• variable's vs. variables (singular possessive vs. plural)
• objects' vs. object's vs. objects (plural possessive vs. singular possessive vs. plural non-possessive)

From what we've read so far:

• 'each of five _____'
  • The word 'five' tells us we're talking about multiple items
  • So we need the plural form: 'variables'
  • Not 'variable's' which would be singular possessive

This eliminates Choice A. But we still need to decide between B, C, and D.

Let's continue reading to see the complete picture:

'each of five variables that characterize _____ movement: displacement, time, initial velocity, final velocity, and acceleration.'

Now let's understand what this is telling us:

• The colon introduces a list of five items:
  • displacement, time, initial velocity, final velocity, and acceleration
  • These five items ARE the five variables being discussed
• These variables 'characterize _____ movement'
  • The word 'movement' comes right after the blank
  • So we need to figure out: whose movement? movement belonging to what?
• The structure is: 'variables that characterize [something's] movement'
  • We're describing movement, but movement needs a possessor
  • The question is whether we need a possessive form or not

Let's examine each possibility:

• 'characterize objects movement' (Choice D)
  • This is grammatically incomplete
  • You can't say 'objects movement' - you need to show the relationship
  • Like you can't say 'the movement the objects' - it needs to be 'the objects' movement'
• 'characterize object's movement' (Choice C)
  • This is singular possessive - one object's movement
  • But we're talking about variables that describe motion in general
  • Not just one specific object
• 'characterize objects' movement' (Choice B)
  • This is plural possessive - the movement belonging to objects
  • This makes sense because these five variables apply to how objects (in general) move
  • The apostrophe after the 's' shows possession for a plural noun

What do we notice about the structure here?

The phrase needs to show that 'movement' belongs to or is associated with 'objects.' This requires a possessive form. Since we're talking about motion in general (not just one object), we need the plural possessive: objects'

So we need Choice B: 'variables that characterize objects' movement'

• 'variables' (plural) fits with 'five variables'
• 'objects'' (plural possessive) correctly shows that the movement belongs to objects in general

GRAMMAR CONCEPT APPLIED

Using Apostrophes to Show Possession

When you want to show that something belongs to or is associated with a noun, you need to use the possessive form with an apostrophe. The placement of the apostrophe depends on whether the noun is singular or plural:

For singular nouns: Add 's

• The object's movement (movement of one object)
• The variable's value (value of one variable)

For plural nouns ending in -s: Add just an apostrophe after the -s

• The objects' movement (movement of multiple objects)
• The variables' values (values of multiple variables)

For plural nouns NOT ending in -s: Add 's

• The children's toys (toys belonging to children)
• The people's choice (choice of the people)

In this question:

• We need 'objects' movement' because:
  • 'Movement' needs a possessor (whose movement?)
  • We're talking about objects in general (plural), not one object
  • For plural possessive, we add the apostrophe after the -s: objects'

Common mistake to avoid:

• Don't confuse plural forms with possessive forms
• 'five variables' = plural (just multiple variables, not showing possession)
• 'objects' movement' = plural possessive (movement belonging to multiple objects)