Problem — Acceleration from Net Force

Problem

A net force of $12\;\text{N}$ is applied to a body of mass $m = 4{,}0\;\text{kg}$. Determine the magnitude of the acceleration.

Solution

Step 1 — Starting data. The problem directly gives the net force (the resultant of all forces) acting on the body: there is no need to combine several forces, because their sum is already $F_{\text{net}} = 12\;\text{N}$.

Step 2 — Newton’s second law. The acceleration is parallel to and in the same direction as the net force, with magnitude

$a = \frac{F_{\text{net}}}{m}$

Step 3 — Numerical substitution.

$a = \frac{12\;\text{N}}{4{,}0\;\text{kg}} = 3{,}0\;\text{m/s}^2$

$\ev{a = 3{,}0\;\mathrm{m/s^2}}$

Links

Topics: Dynamics Concepts: Newton’s second law · Acceleration