Free CMAS Science Questions and Answers — Questions and Answers
Question 1: Curtains in theaters prevent sound waves from being reflected as echoes. Which model best explains why curtains prevent echoes?
- A ball thrown toward a surface will come in contact faster with a soft surface than with a hard surface.
- A ball thrown at a surface will hit with a greater force on a soft surface than on a hard surface.
- A ball rolled across a surface will roll more quickly on a hard surface than on a soft surface.
- A ball dropped on a surface will bounce more on a hard surface than on a soft surface. (Correct answer)
Correct answer: A ball dropped on a surface will bounce more on a hard surface than on a soft surface.
Echoes occur when sound waves reflect off hard, smooth surfaces. Curtains are soft and absorbent, meaning they absorb sound energy rather than reflecting it. This is analogous to a ball bouncing less (or not at all) on a soft surface compared to a hard surface, where it would bounce significantly more, representing reflection.
Question 2: Which of the following moons of Jupiter is the closest to the planet?
- Callisto
- Ganymede
- Europa
- Io (Correct answer)
Correct answer: Io
Io is the innermost of Jupiter's four largest moons, known as the Galilean moons. Its orbital distance is approximately 421,700 km from Jupiter's center, making it closer to the planet than Europa, Ganymede, and Callisto, which orbit at progressively greater distances.
Question 3: What forces are primarily responsible for keeping the globe floating in place over its base?
- Gravitational force and magnetic force
- Frictional force and electrical force
- Gravitational force and frictional force
- Magnetic force and gravitational force (Correct answer)
Correct answer: Magnetic force and gravitational force
For a globe to float (levitate) over its base, there must be an upward force counteracting the downward pull of gravity. This upward force is typically provided by magnetic repulsion from magnets within the base and the globe, balancing the gravitational force to keep it suspended in place.
Question 4: What principle explains why the falling magnets are pushed back up by the magnets at the bottom of the rod?
- Friction
- Magnetic repulsion (Correct answer)
- Gravitational attraction
- Electrical force
Correct answer: Magnetic repulsion
Magnets exert forces on each other, and when like poles (e.g., North-North or South-South) face each other, they repel, pushing each other apart. In this setup, the falling magnets are pushed back up because their poles align with the poles of the stationary magnets at the bottom of the rod in a way that causes magnetic repulsion.
Question 5: What was the primary purpose of the Voyager 2 mission as indicated by its trajectory through the solar system?
- To establish a permanent base on Mars
- To study the outer planets and their moons (Correct answer)
- To search for extraterrestrial life
- To map the entire solar system
Correct answer: To study the outer planets and their moons
Voyager 2 was specifically designed and launched to conduct a 'grand tour' of the outer solar system. Its unique trajectory allowed it to visit all four gas giants—Jupiter, Saturn, Uranus, and Neptune—providing unprecedented data and images of these planets and their numerous moons, fulfilling its primary purpose of studying the outer planets.
Free CMAS Science Questions and Answers
Curtains in theaters prevent sound waves from being reflected as echoes.
Which model best explains why curtains prevent echoes?