Physics · GRAVITATION

If \( \mathbf{r}_1 \) and \( \mathbf{r}_2 \) are the position vectors of two point masses \( m_1 \) and \( m_2 \) respectively, and \( \mathbf{r} = \mathbf{r}_2 - \mathbf{r}_1 \), then in vector notation, the gravitational force \( \mathbf{F}_{12} \) exerted on \( m_1 \) by \( m_2 \) is correctly given by:

1. \( \mathbf{F}_{12} = -G \frac{m_1 m_2}{|\mathbf{r}|^3} \mathbf{r} \)
2. \( \mathbf{F}_{12} = -G \frac{m_1 m_2}{|\mathbf{r}|^2} \mathbf{r} \)
3. \( \mathbf{F}_{12} = G \frac{m_1 m_2}{|\mathbf{r}|^2} \mathbf{r} \)
4. \( \mathbf{F}_{12} = G \frac{m_1 m_2}{|\mathbf{r}|^3} \mathbf{r} \)