Question

when net force is equal to zero, a change in motion will not occur. what amount of force should be added to the right side of the box if we do not want it to move? 30 n more or less than 30 n

Explanation:

Step1: Understand net force concept

Net force \(F_{net}=F_1 + F_2\) (where \(F_1\) and \(F_2\) are forces acting on an object). If \(F_{net}=0\), then \(F_1=-F_2\). Here, \(F_1 = 30N\) (to the right).

Step2: Calculate the required force

Let the force on the left be \(F_{left}\) and on the right be \(F_{right}\). We want \(F_{net}=F_{right}+F_{left}=0\). Given \(F_{left}\) (assuming the unknown force on the left is \(x\) and \(F_{right} = 30N\)). For \(F_{net}=0\), if we consider the left - acting force as \(x\) (magnitude) and direction (opposite to the right - acting force), then \(30N\) (right) and \(x\) (left) must satisfy \(30 - x=0\) (taking right as positive). So \(x = 30N\). If we add a force to the right, to keep \(F_{net}=0\), the net force from the right side (original \(30N\) plus the added force \(F_{add}\)) and the left - side force (\(30N\)) must balance. Let the left - side force \(F_{left}=30N\). We want \((30 + F_{add})-30=0\).

Answer:

\(30N\)