Question

5.1.2 exam: semester 2 exam
how does the energy of the comet change as it moves from point a to point b?
a. ke increases, gpe decreases
b. ke increases, gpe increases
c. ke decreases, gpe increases

Explanation:

Step1: Understand the relationship between KE and GPE

When a comet moves closer to the sun (a massive body), gravitational potential energy (GPE) decreases. According to the law of conservation of mechanical energy (assuming no non - conservative forces like air resistance, which is a good approximation in space), \(KE + GPE=\text{constant}\).

Step2: Analyze the motion from A to B

As the comet moves from A to B, it is moving closer to the sun. So, \(GPE\) (gravitational potential energy) decreases. Since \(KE+GPE = \text{constant}\), if \(GPE\) decreases, \(KE\) (kinetic energy) must increase.

Answer:

A. \(KE\) increases, \(GPE\) decreases