Final answer:
To determine the force of friction on the 7 kg box with a 47N force applied and an acceleration of 3 m/s², use Newton's second law. The net force calculated (21 N) and the applied force allow us to find the frictional force to be 26 N.
Step-by-step explanation:
The question asks for the force of friction (Ff) acting on a 7 kg box when a 47N force is applied, causing it to accelerate at 3 m/s². To find the frictional force, we can use Newton's second law, which states that the net force acting on an object is equal to the mass (m) of the object multiplied by its acceleration (a). The formula is Fnet = ma. In this case:
Fnet = m * a = 7 kg * 3 m/s² = 21 N.
The net force is the difference between the applied force and the force of friction, which can be written as:
Fnet = Fapplied - Ffriction
Substituting the given values:
21 N = 47N - Ffriction
To find the force of friction, we rearrange the equation:
Ffriction = 47N - 21 N = 26 N.
Therefore, the force of friction is 26 N.