Bumper car 1 (296 kg) is moving east at [tex]3.74 \, \text{m/s}[/tex]. Bumper car 2 (222 kg) is moving east at [tex]1.85 \, \text{m/s}[/tex].

If the cars have an elastic collision, what is the final velocity of car 1?

A. [tex]v_{1f} = \left( \frac{m_1 - m_2}{m_1 + m_2} \right) v_{1i} + \left( \frac{2m_2}{m_1 + m_2} \right) v_{2i}[/tex]

B. [tex]v_{2f} = \left( \frac{2m_1}{m_1 + m_2} \right) v_{1i} + \left( \frac{m_2 - m_1}{m_1 + m_2} \right) v_{2i}[/tex]



Answer :

To find the final velocity of bumper car 1 after an elastic collision with bumper car 2, we can use the given formula:

[tex]\[ v_{1f} = \left( \frac{m_1 - m_2}{m_1 + m_2} \right) v_{1i} + \left( \frac{2m_2}{m_1 + m_2} \right) v_{2i} \][/tex]

Where:
- [tex]\( m_1 \)[/tex] is the mass of car 1,
- [tex]\( m_2 \)[/tex] is the mass of car 2,
- [tex]\( v_{1i} \)[/tex] is the initial velocity of car 1,
- [tex]\( v_{2i} \)[/tex] is the initial velocity of car 2,
- [tex]\( v_{1f} \)[/tex] is the final velocity of car 1.

Given the values:
- [tex]\( m_1 = 296 \, \text{kg} \)[/tex]
- [tex]\( m_2 = 222 \, \text{kg} \)[/tex]
- [tex]\( v_{1i} = 3.74 \, \text{m/s} \)[/tex]
- [tex]\( v_{2i} = 1.85 \, \text{m/s} \)[/tex]

Let's substitute these values into the formula and solve for [tex]\( v_{1f} \)[/tex]:

1. Calculate the first term:
[tex]\[ \left( \frac{m_1 - m_2}{m_1 + m_2} \right) v_{1i} \][/tex]
Substitute the given values:
[tex]\[ \left( \frac{296 - 222}{296 + 222} \right) 3.74 \][/tex]
[tex]\[ \left( \frac{74}{518} \right) 3.74 \][/tex]

2. Calculate the fraction:
[tex]\[ \frac{74}{518} \approx 0.1429 \][/tex]

3. Multiply by [tex]\( v_{1i} \)[/tex]:
[tex]\[ 0.1429 \times 3.74 \approx 0.5345 \][/tex]

4. Calculate the second term:
[tex]\[ \left( \frac{2m_2}{m_1 + m_2} \right) v_{2i} \][/tex]
Substitute the given values:
[tex]\[ \left( \frac{2 \times 222}{296 + 222} \right) 1.85 \][/tex]
[tex]\[ \left( \frac{444}{518} \right) 1.85 \][/tex]

5. Calculate the fraction:
[tex]\[ \frac{444}{518} \approx 0.8571 \][/tex]

6. Multiply by [tex]\( v_{2i} \)[/tex]:
[tex]\[ 0.8571 \times 1.85 \approx 1.5866 \][/tex]

7. Sum the two terms to find [tex]\( v_{1f} \)[/tex]:
[tex]\[ v_{1f} = 0.5345 + 1.5866 \][/tex]
[tex]\[ v_{1f} \approx 2.12 \, \text{m/s} \][/tex]

Thus, the final velocity of car 1 is approximately [tex]\( 2.12 \, \text{m/s} \)[/tex].