Question

the momentum of a rock rolling down a hill increases as it goes down the hill, why is this?

Explanation:

Step1: Recall the formula for momentum

The formula for momentum is \(p = mv\), where \(p\) is momentum, \(m\) is mass, and \(v\) is velocity.

Step2: Analyze the mass and velocity of the rock

The mass \(m\) of the rock remains constant (assuming no parts break off). As the rock rolls down the hill, it accelerates due to gravity. Acceleration means an increase in velocity \(v\).

Step3: Determine the effect on momentum

Since \(p = mv\) and \(m\) is constant while \(v\) increases, the product \(mv\) (momentum \(p\)) also increases.

Answer:

The momentum of the rock increases because its velocity increases as it rolls down the hill (while its mass remains constant), and momentum \(p = mv\) (where \(m\) is mass and \(v\) is velocity).