Question

a cars engine pushes with 45n to the right. if it is at equilibrium, how much air friction is there and what is the cars acceleration? a 25kg object accelerates at 5 m/s². find the force.

Explanation:

Step1: Analyze the first problem (car at equilibrium)

When an object is at equilibrium, the net force \(F_{net}=0\). The engine force \(F_{engine} = 45N\) (to the right). Let the air - friction force be \(F_{friction}\). Using \(F_{net}=F_{engine}-F_{friction}\), since \(F_{net} = 0\), we have \(F_{friction}=F_{engine}\). Also, from Newton's second law \(F_{net}=ma\), and since \(F_{net} = 0\), \(a = 0\).

Step2: Solve the second problem (force calculation)

Use Newton's second law \(F = ma\). Given \(m = 25kg\) and \(a=5m/s^{2}\). Substitute the values into the formula: \(F=(25kg)\times(5m/s^{2})\).

Answer:

• For the car: The air - friction is \(45N\) (to the left) and the acceleration \(a = 0m/s^{2}\).
• For the \(25kg\) object: \(F = 125N\)