Conservation of Mechanical Energy: Energy Skate Park A PhET Simulation k:

Conservation of Mechanical Energy: Energy Skate Park A PhET Simulation k: https://phet.colorado.edu/sims/html/energy-skate-park-basics/latest/energy-skate-park- asics_en.html rocedures: 1. Position the skater at the edge of the ramp. 2. Let him slide on the ramp. 3. Observe the skater as he skates on the ramp. Jestions: 1. What type/s of mechanical energy is/are present in your activity? Answer: Conservation of mechanical energy 2. What is the velocity of the skater at its maximum height? 3. What happens to the velocity of the skater when it reaches the bottom part of the ramp? Did it increase? Decrease? Or Zero? 4. Complete the diagram below. Underline the correct answer. KE: (increases, decreases) PE: (increases, decreases) Has maximum (KE, PE) Has zero (KE, PE) KE: (increases, decreases) PE Full text: 1088 Has maximum (KE, PE) (KE, PE) Has zero

The Correct Answer and Explanation is:

Correct Answers

1. Skater moving down the ramp (Top Left):

• KE: <u>increases</u>
• PE: <u>decreases</u>

2. Skater at the bottom of the ramp (Top Right):

• Has maximum (<u>KE</u>, PE)
• Has zero (KE, <u>PE</u>)

3. Skater moving up the ramp (Bottom Left):

• KE: <u>decreases</u>
• PE: <u>increases</u>

4. Skater at the top of the ramp (Bottom Right):

• Has maximum (KE, <u>PE</u>)
• Has zero (<u>KE</u>, PE)

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Explanation

This activity demonstrates the law of conservation of mechanical energy, which states that in an isolated system (without friction), the total mechanical energy remains constant. Mechanical energy is the sum of an object’s Kinetic Energy (KE) and Potential Energy (PE).

• Potential Energy (PE) is the energy of position, calculated as PE = mgh (mass × gravity × height). It is highest when the skater is at the highest point of the ramp and zero at the lowest point.
• Kinetic Energy (KE) is the energy of motion, calculated as KE = ½mv² (½ × mass × velocity²). It is highest when the skater is moving fastest and zero when the skater is momentarily at rest.

As the skater moves, energy continuously transforms between these two forms:

1. Skater moving down (Top Left): As the skater slides down the ramp, their height (h) decreases, causing their Potential Energy (PE) to decrease. This lost potential energy is converted into kinetic energy. Consequently, their velocity (v) increases, causing their Kinetic Energy (KE) to increase.
2. Skater at the bottom (Top Right): At the very bottom of the ramp, the skater is at the lowest possible height (h=0). Therefore, their Potential Energy (PE) is zero. At this point, all the initial potential energy has been converted into kinetic energy, so the skater reaches their maximum velocity. This means their Kinetic Energy (KE) is at its maximum.
3. Skater moving up (Bottom Left): As the skater moves up the other side of the ramp, their height (h) increases, causing their Potential Energy (PE) to increase. This gain in potential energy comes from the conversion of kinetic energy. As a result, the skater’s velocity (v) decreases, causing their Kinetic Energy (KE) to decrease.
4. Skater at the top (Bottom Right): When the skater reaches the highest point on the other side, they momentarily stop (v=0) before changing direction. At this peak, their Kinetic Energy (KE) is zero. Because they are at their maximum height, their Potential Energy (PE) is at its maximum, equal to the initial potential energy they started with.