F = m * a

Where:

* F is the force (65 N)

* m is the mass (10 kg)

* a is the acceleration (what we want to find)

To solve for acceleration (a), rearrange the formula:

a = F / m

Now plug in the values:

a = 65 N / 10 kg

a = 6.5 m/s²

Therefore, the acceleration of the boulder is 6.5 m/s².