Question

8th grade science test: unit 2: defining energy
instructions: read each question carefully. answer in complete sentences where appropriate. write your responses directly below each question or on a separate piece of paper (please label each question and staple to this sheet.).

1. explain the difference between gravitational potential energy, elastic potential energy, and kinetic energy. in your answer, describe: what causes each type of energy (e.g., position, motion, or changing of shape) at least one real - world example of each.

2.look at the roller coaster diagram below (points a - e). the roller coaster starts at point a and moves along the track. using what you know about potential and kinetic energy, describe how the energy of the roller coaster changes as it travels from a→b→c→d→e. in your response, explain: where the potential energy is greatest and why. where the kinetic energy is greatest and why. how energy is transformed between potential and kinetic forms along the track. you may reference specific points (a - e) in your explanation.

1. using what you know about the formulas for potential and kinetic energy, explain how height and mass affects gravitational potential energy. then, compare two scenarios: a 2.5 kg ball dropped from 10.7 meters high a 3.7 kg ball dropped from 7.5 meters high which has more potential energy and why? (show your work for the math)

Explanation:

Step1: Calculate gravitational potential energy for first ball

The formula for gravitational potential energy is \(U = mgh\), where \(m\) is mass, \(g = 9.8\space m/s^{2}\), and \(h\) is height.
For the first ball: \(m_1=2.5\space kg\), \(h_1 = 10.7\space m\)
\(U_1=m_1gh_1=2.5\times9.8\times10.7\)
\(U_1 = 2.5\times104.86=262.15\space J\)

Step2: Calculate gravitational potential energy for second ball

For the second ball: \(m_2 = 3.7\space kg\), \(h_2=7.5\space m\)
\(U_2=m_2gh_2=3.7\times9.8\times7.5\)
\(U_2=3.7\times73.5 = 271.95\space J\)

Step3: Compare the two potential energies

Since \(U_1 = 262.15\space J\) and \(U_2=271.95\space J\)

Answer:

The \(3.7\space kg\) ball dropped from \(7.5\space m\) has more potential energy.