HSA Physical Science 1 — Questions and Answers
Question 1: Which of the following is an example of a physical change?
- Burning wood
- Rusting iron
- Cutting paper (Correct answer)
- Baking a cake
Correct answer: Cutting paper
Cutting paper only changes the shape and size of the material without producing a new substance, making it a physical change.
Question 2: A student pushes a box across the floor. The force that opposes this motion is called:
- Gravity
- Friction (Correct answer)
- Inertia
- Tension
Correct answer: Friction
Friction is the force that opposes the motion of objects sliding against each other, resisting the push on the box.
Question 3: Which state of matter has a definite volume but no definite shape?
- Solid
- Liquid (Correct answer)
- Gas
- Plasma
Correct answer: Liquid
Liquids have a definite volume but take the shape of whatever container they are placed in, giving them no definite shape.
Question 4: An object has a mass of 50 grams and a volume of 10 cm³. What is its density?
- 5 g/cm³ (Correct answer)
- 500 g/cm³
- 0.2 g/cm³
- 60 g/cm³
Correct answer: 5 g/cm³
Density equals mass divided by volume: 50 g ÷ 10 cm³ = 5 g/cm³.
Question 5: Which of the following is the best conductor of electricity?
- Wood
- Plastic
- Rubber
- Copper (Correct answer)
Correct answer: Copper
Copper is a metal with free-moving electrons that allow electrical current to flow easily through it, making it an excellent conductor.
Question 6: When a guitar string vibrates, it produces sound. This sound travels to your ears as:
- Light waves
- Mechanical waves (Correct answer)
- Electromagnetic waves
- Radiation
Correct answer: Mechanical waves
Sound is a mechanical wave that requires a medium (such as air) to travel through, unlike electromagnetic waves which can travel through a vacuum.
Question 7: According to Newton's First Law of Motion, an object at rest will:
- Begin moving on its own over time
- Stay at rest unless acted on by an unbalanced force (Correct answer)
- Slow down due to gravity
- Always accelerate downward
Correct answer: Stay at rest unless acted on by an unbalanced force
Newton's First Law (inertia) states that an object at rest stays at rest and an object in motion stays in motion unless an unbalanced (net) force acts on it.
HSA Physical Science 1
Which of the following is an example of a physical change?