PSSA PSSA Physical Science 2 â Questions and Answers
Question 1: What is the difference between speed and velocity?
- Speed is measured in km/h; velocity is measured in m/s
- Speed describes how fast an object moves; velocity includes speed and direction (Correct answer)
- Speed applies to moving objects; velocity applies to stationary objects
- Speed is constant; velocity always changes
Correct answer: Speed describes how fast an object moves; velocity includes speed and direction
Speed is the magnitude of motion (how fast), while velocity is a vector that includes both speed and direction.
Question 2: What does the periodic table organize elements by?
- Alphabetical order by element name
- Increasing atomic number and similar chemical properties (Correct answer)
- Decreasing mass from left to right
- The order in which elements were discovered
Correct answer: Increasing atomic number and similar chemical properties
The periodic table organizes elements in order of increasing atomic number, with elements in the same column sharing similar chemical properties.
Question 3: Which of the following describes a chemical change?
- Ice melting into water
- Paper being torn into pieces
- Sugar dissolving in water
- Iron rusting (Correct answer)
Correct answer: Iron rusting
Iron rusting is a chemical change because it involves a chemical reaction that creates a new substance (iron oxide).
Question 4: What is the formula for calculating work?
- Work = Force ÷ Distance
- Work = Mass à Acceleration
- Work = Force à Distance (Correct answer)
- Work = Power à Time
Correct answer: Work = Force à Distance
Work is calculated by multiplying the force applied to an object by the distance the object moves in the direction of the force (W = F Ã d).
Question 5: What are the three states of matter?
- Solid, liquid, plasma
- Solid, liquid, gas (Correct answer)
- Liquid, vapor, crystal
- Dense, fluid, gaseous
Correct answer: Solid, liquid, gas
The three common states of matter are solid (fixed shape and volume), liquid (fixed volume, variable shape), and gas (variable shape and volume).
Question 6: What is kinetic energy?
- Energy stored in an object due to its position
- Energy an object possesses due to its motion (Correct answer)
- Energy released during chemical reactions
- Energy transferred through electromagnetic waves
Correct answer: Energy an object possesses due to its motion
Kinetic energy is the energy an object has because of its motion, calculated as KE = œmv².
PSSA PSSA Physical Science 2
What is the difference between speed and velocity?