Question

what is the magnitude (size) of the missing force in the figure diagrammed below?
hint: when using the ( f = ma ) formula, ( f ) is net force.
answer: type your answer... choose your answer...

Explanation:

Step1: Calculate the net force

According to \(F = ma\), where \(m = 5\space kg\) and \(a=4\space m/sec^{2}\).
\(F_{net}=ma=5\times4 = 20\space N\) (to the right)

Step2: Set up the force - equation

Let the unknown force be \(F\). The forces acting on the object: forces to the right are \(18 + 12\), and the force to the left is \(F\).
\(F_{net}=(18 + 12)-F\)

Step3: Solve for \(F\)

Since \(F_{net}=20\), we have \(20=(18 + 12)-F\).
First, simplify the right - hand side: \(18+12 = 30\). Then the equation becomes \(20 = 30 - F\).
Add \(F\) to both sides: \(20+F=30\).
Subtract 20 from both sides: \(F = 30 - 20\)

Answer:

\(10\)