Stored Energy Changes I Quick Check
1. A horseshoe magnet is moved toward a pile of iron shavings. The iron shavings divide and attach to both ends of the magnet. How does the kinetic energy of the system change?
Answer: A. Kinetic energy increases because iron shavings move in the direction of magnetic force.
2. Two bar magnets are held in place with their north poles facing each other. Both magnets are released at the same time. Which statement describing changes to the energy of the system is correct?
Answer: A. Potential energy decreases, and kinetic and thermal energy increase.
3. Two bar magnets are held in place in the configuration shown. If the magnets are pulled apart, which statement correctly describes the changes that will take place in the energy of the system?
Answer: D. Potential energy increases because movement is in the opposite direction of the magnetic field.
4. The south poles of two bar magnets are 10 cm from each other. The poles are brought to 5 cm apart and then moved back to their original positions. How does the energy of the system change?
Answer: A. The total change in the energy of the system is zero.
5. A community seeks to develop a maglev train operation. Which of the following is most likely their technical motivation for choosing this option?
Answer: A. They seek a rail line not affected by friction.
Stored Energy Changes II Quick Check
1. Two magnets are held apart. Once released, the South Pole of one magnet moves toward the North Pole of another magnet until the magnets collide. How does the graph reflect the changes in energy that occur?
Answer: C. Kinetic energy and velocity are at zero when the magnets are held apart, and both increase rapidly when they are released and move together. Energy stored in the magnetic field decreases.
2. Two magnets are placed on a table, and they immediately move to attach to each other. Which statement is correct about the energies in the system?
Answer: C. The energy stored in the system is converted to kinetic, thermal, and sound energy.
3. A magnet is moved close to a rubber band. How does the energy stored in the magnetic field change?
Answer: C. The energy stored in the magnetic field does not change.
4. Two donut-shaped magnets are stacked on top of each other with a wooden dowel in the center. The south poles of the magnets are facing each other. Once the upper magnet is released, it accelerates downward and stops 1 cm above the lower magnet. How does the energy stored in the magnetic field change?
Answer: B. Some of the energy stored is converted into kinetic and thermal energy.
5. Which interaction between magnets demonstrates the greatest change in kinetic energy?
Answer: A. Two attracting magnets are released while moving towards one another.
These answers resulted in two 100% grades for me.
Please base your answers off of the WRITTEN answers rather than the answer letters written here. It may vary.
I hope this helps someone!!
pepis speakin facts, i've made those mistakes wayyyy too many times. anybody reading this, PLEASE do not go based off the letter they mix them up. silly goose.
GUys these are all correct. Just make sure to read the answers and match them and NOT follow the letters. The test might mix the order up.
Thank You!