The net external force on a lawn mower of mass 24 kg is 51 N parallel to the ground. What is its acceleration?

1. Newton's second law gives the acceleration as the net external force divided by the mass. 2. Identify the knowns: the net external force is 51 N and the mass is 24 kg. 3. Substitute the values: (51 N) / (24 kg). 4. Writing the newton in base units, that is (51 kg times m/s^2) / (24 kg) = 2.1 m/s^2. 5. The acceleration points in the same direction as the net force, so it is parallel to the ground. 6. Dividing the mass by the force instead gives 0.47, with the units upside down. _Source: OpenStax College Physics (CC BY 4.0), Ch 4 "Dynamics: Force and Newton's Laws of Motion", section 4.3 Newton's Second Law of Motion: Concept of a System_