EOC Physics 2 — Questions and Answers
Question 1: A 2 kg object is lifted 5 meters above the ground. What is its gravitational potential energy? (g = 10 m/s²)
- 10 J
- 25 J
- 100 J (Correct answer)
- 7 J
Correct answer: 100 J
Gravitational PE = mgh = 2 × 10 × 5 = 100 J.
Question 2: Which of the following best describes the Law of Conservation of Energy?
- Energy can be created from nothing in isolated systems
- Total energy in an isolated system remains constant (Correct answer)
- Kinetic energy always converts to thermal energy
- Potential energy increases as objects speed up
Correct answer: Total energy in an isolated system remains constant
The Law of Conservation of Energy states that energy cannot be created or destroyed; the total energy of an isolated system remains constant.
Question 3: What type of wave requires a medium to travel through?
- Electromagnetic wave
- Light wave
- Mechanical wave (Correct answer)
- Radio wave
Correct answer: Mechanical wave
Mechanical waves, such as sound and water waves, require a medium (solid, liquid, or gas) to propagate, unlike electromagnetic waves which can travel through a vacuum.
Question 4: In a wave, what is the distance between two consecutive crests called?
- Amplitude
- Frequency
- Wavelength (Correct answer)
- Period
Correct answer: Wavelength
Wavelength is the distance between two consecutive points in phase on a wave, such as from crest to crest or trough to trough.
Question 5: A 4 kg object has a kinetic energy of 50 J. What is its approximate speed?
- 2.5 m/s
- 5 m/s (Correct answer)
- 10 m/s
- 25 m/s
Correct answer: 5 m/s
KE = ½mv², so 50 = ½(4)v², giving v² = 25 and v = 5 m/s.
Question 6: Which color of visible light has the highest frequency?
- Red
- Green
- Yellow
- Violet (Correct answer)
Correct answer: Violet
Violet light has the highest frequency (and shortest wavelength) in the visible spectrum, while red light has the lowest frequency.
Question 7: When a wave moves from deep water to shallow water, what happens to its speed?
- It increases
- It decreases (Correct answer)
- It stays the same
- It doubles
Correct answer: It decreases
Water waves slow down when moving from deep to shallow water because the wave interacts more with the ocean floor, reducing wave speed.
EOC Physics 2
A 2 kg object is lifted 5 meters above the ground.
What is its gravitational potential energy? (g = 10 m/s²)