1. Convert mass to kilograms:

* 7.0 g = 0.007 kg (since 1 kg = 1000 g)

2. Use Newton's Second Law of Motion:

* Force (F) = Mass (m) * Acceleration (a)

3. Solve for acceleration (a):

* a = F / m

* a = 2.1 N / 0.007 kg

* a = 300 m/s²

Therefore, the acceleration of the rifle bullet is 300 m/s².