A semitruck [tex]\(( m=20,000 \, \text{kg} )\)[/tex] is [tex]\(10 \, \text{m}\)[/tex] from a car [tex]\(( m=2000 \, \text{kg} )\)[/tex]. What is the force of gravity between them? [tex]\(\left( G=6.67 \times 10^{-11} \, \text{N} \cdot \text{m}^2 / \text{kg}^2 \right)\)[/tex]

A. [tex]\(1.22 \times 10^{-5} \, \text{N}\)[/tex]

B. [tex]\(1.22 \times 10^{-4} \, \text{N}\)[/tex]

C. [tex]\(2.67 \times 10^{-5} \, \text{N}\)[/tex]

D. [tex]\(2.67 \times 10^{-4} \, \text{N}\)[/tex]



Answer :

To determine the gravitational force between the semitruck and the car, we'll use Newton's law of universal gravitation. The formula for the gravitational force [tex]\( F \)[/tex] is given by:

[tex]\[ F = G \frac{m_1 m_2}{r^2} \][/tex]

where:
- [tex]\( G \)[/tex] is the gravitational constant, [tex]\( 6.67 \times 10^{-11} \, \text{N} \cdot \text{m}^2 / \text{kg}^2 \)[/tex],
- [tex]\( m_1 \)[/tex] is the mass of the semitruck, [tex]\( 20{,}000 \, \text{kg} \)[/tex],
- [tex]\( m_2 \)[/tex] is the mass of the car, [tex]\( 2{,}000 \, \text{kg} \)[/tex],
- [tex]\( r \)[/tex] is the distance between the semitruck and the car, [tex]\( 10 \, \text{m} \)[/tex].

Let's plug in the given values into the formula:

1. Calculate the product of the masses:
[tex]\[ m_1 \cdot m_2 = 20{,}000 \, \text{kg} \times 2{,}000 \, \text{kg} = 40{,}000{,}000 \, \text{kg}^2 \][/tex]

2. Calculate the square of the distance:
[tex]\[ r^2 = (10 \, \text{m})^2 = 100 \, \text{m}^2 \][/tex]

3. Plug these values and [tex]\( G \)[/tex] into the formula:
[tex]\[ F = 6.67 \times 10^{-11} \cdot \frac{40{,}000{,}000}{100} \][/tex]

4. Simplify the fraction:
[tex]\[ \frac{40{,}000{,}000}{100} = 400{,}000 \][/tex]

5. Multiply by the gravitational constant [tex]\( G \)[/tex]:
[tex]\[ F = 6.67 \times 10^{-11} \cdot 400{,}000 \][/tex]

[tex]\[ F = 2.668 \times 10^{-5} \, \text{N} \][/tex]

Thus, the gravitational force between the semitruck and the car is approximately [tex]\( 2.67 \times 10^{-5} \, \text{N} \)[/tex].

Therefore, the correct answer is:

C. [tex]\( 2.67 \times 10^{-5} \, \text{N} \)[/tex]