Answered

A car has a momentum of [tex]$20,000 \, kg \cdot m / s$[/tex]. What would the car's momentum be if its velocity doubles?

A. [tex]$10,000 \, kg \cdot m / s$[/tex]

B. [tex][tex]$20,000 \, kg \cdot m / s$[/tex][/tex]

C. [tex]$40,000 \, kg \cdot m / s$[/tex]



Answer :

Let's solve the problem step-by-step.

First, we need to understand the relationship between momentum and velocity. Momentum ([tex]\( p \)[/tex]) is defined as:
[tex]\[ p = m \cdot v \][/tex]
where [tex]\( m \)[/tex] is the mass of the car and [tex]\( v \)[/tex] is its velocity.

Given that the initial momentum ([tex]\( p_{\text{initial}} \)[/tex]) of the car is [tex]\( 20,000 \, \text{kg} \cdot \text{m} / \text{s} \)[/tex]:
[tex]\[ p_{\text{initial}} = 20,000 \, \text{kg} \cdot \text{m} / \text{s} \][/tex]

If the velocity of the car doubles, we can denote the new velocity as [tex]\( 2v \)[/tex]. Since the mass of the car remains unchanged, we can write the new momentum ([tex]\( p_{\text{final}} \)[/tex]) as:
[tex]\[ p_{\text{final}} = m \cdot (2v) \][/tex]

Notice that doubling the velocity will also double the momentum. Therefore:
[tex]\[ p_{\text{final}} = 2 \cdot (m \cdot v) = 2 \cdot p_{\text{initial}} \][/tex]

Given [tex]\( p_{\text{initial}} = 20,000 \, \text{kg} \cdot \text{m} / \text{s} \)[/tex]:
[tex]\[ p_{\text{final}} = 2 \cdot 20,000 \, \text{kg} \cdot \text{m} / \text{s} \][/tex]
[tex]\[ p_{\text{final}} = 40,000 \, \text{kg} \cdot \text{m} / \text{s} \][/tex]

Therefore, if the car's velocity doubles, its momentum would be:
[tex]\[ 40,000 \, \text{kg} \cdot \text{m} / \text{s} \][/tex]

So, the correct answer is:
[tex]\[ 40,000 \, \text{kg} \cdot \text{m} / \text{s} \][/tex]