UPCAT General Science (Extended) — Scientific Method & MeasurementFlash Cards

A student notices that plants near the window grow taller than those in the corner. What is the first step in the scientific method they should follow?

Ask a Question: The student should formulate a clear question like 'Does the amount of sunlight affect plant growth?' This is the first step in the scientific method where we identify what we want to investigate based on our observation.

What is the difference between a hypothesis and a prediction in scientific investigation?

A hypothesis is a testable explanation for an observation (e.g., 'Plants need sunlight to grow properly'), while a prediction is a specific, measurable outcome you expect if the hypothesis is correct (e.g., 'Plants given 6 hours of sunlight daily will grow 2cm taller than plants given no direct sunlight').

In an experiment testing if fertilizer affects plant growth, identify the independent variable, dependent variable, and one controlled variable.

Independent Variable: Type/amount of fertilizer (what the scientist changes) Dependent Variable: Plant height/growth (what responds to the change) Controlled Variable: Amount of water, sunlight, soil type, temperature (factors kept constant)

Convert 2.5 kilometers to meters using the metric system.

2.5 km = 2,500 m Solution: Move decimal point 3 places to the right when converting from kilo (10³) to base unit. 2.5 × 1,000 = 2,500 meters Remember: Kilo means 1,000 times the base unit.

What are the 7 base quantities and their SI units?

1. Length - meter (m) 2. Mass - kilogram (kg) 3. Time - second (s) 4. Electric Current - ampere (A) 5. Temperature - kelvin (K) 6. Amount of Substance - mole (mol) 7. Luminous Intensity - candela (cd) These form the foundation of all other measurements in science.

Why do scientists conduct multiple trials in experiments?

Multiple trials help ensure results are reliable and accurate by: 1. Reducing the effect of random errors 2. Identifying outliers or unusual results 3. Calculating averages for more precise data 4. Increasing confidence in conclusions 5. Making experiments reproducible by other scientists

Convert 750 milliliters to liters.

750 mL = 0.75 L Solution: Move decimal point 3 places to the left when converting from milli (10⁻³) to base unit. 750 ÷ 1,000 = 0.75 liters Remember: Milli means 1/1,000 of the base unit.

What is the difference between a scientific law and a scientific theory?

Scientific Law: Describes what happens in nature (e.g., 'Objects fall toward Earth') Scientific Theory: Explains why something happens (e.g., 'Gravity causes objects to fall toward Earth due to mass attraction') Both are well-tested, but theories provide explanations while laws describe patterns.

How do you measure the volume of an irregular solid like a stone?

Use the Displacement Method: 1. Fill a graduated cylinder partially with water and record initial volume 2. Carefully submerge the stone completely 3. Record the new water level 4. Volume of stone = Final volume - Initial volume This follows Archimedes' Principle: displaced water equals object volume.

Convert 25°C to Fahrenheit and Kelvin.

To Fahrenheit: F = (C × 9/5) + 32 = (25 × 9/5) + 32 = 45 + 32 = 77°F To Kelvin: K = C + 273 = 25 + 273 = 298 K Remember: Kelvin is always positive and used in scientific calculations.

What is the difference between mass and weight?

Mass: Amount of matter in an object (measured in kg), remains constant everywhere Weight: Force of gravity on an object (measured in N), changes with location Formula: Weight = Mass × Gravity (W = mg) Example: Your mass is the same on Earth and Moon, but weight is less on Moon due to weaker gravity.

Calculate the density of a material if 50g occupies 25 cm³.

Density = Mass ÷ Volume = 50g ÷ 25 cm³ = 2 g/cm³ This material is denser than water (1 g/cm³), so it will sink in water. Density helps identify materials and predict if objects will float or sink.

What are the four fundamental forces of nature?

1. Gravitational Force - attracts objects with mass 2. Electromagnetic Force - acts between charged particles 3. Strong Nuclear Force - holds atomic nuclei together 4. Weak Nuclear Force - responsible for radioactive decay These forces explain all interactions between matter in the universe.

Why is it important to conduct background research before forming a hypothesis?

Background research helps you: 1. Understand what is already known about the topic 2. Avoid repeating experiments that have been done 3. Form a more educated hypothesis 4. Design better experiments 5. Use reliable sources like scientific journals and books 6. Build on previous scientific knowledge

Convert 3.2 × 10⁶ millimeters to kilometers.

3.2 × 10⁶ mm = 3.2 km Solution: From milli to kilo requires moving 6 decimal places left (10⁻³ to 10³) 3.2 × 10⁶ ÷ 10⁶ = 3.2 Or: 3,200,000 mm ÷ 1,000,000 = 3.2 km

What makes an experiment 'controlled' and why is this important?

A controlled experiment: 1. Changes only ONE variable at a time (independent variable) 2. Keeps all other factors constant (controlled variables) 3. Measures the response (dependent variable) This ensures any changes observed are due to the independent variable, not other factors, making results valid and reliable.

Calculate the work done when a 10N force moves an object 5 meters in the direction of the force.

Work = Force × Distance = 10 N × 5 m = 50 J (joules) Work is done only when force causes movement in the same direction. If force is perpendicular to movement, no work is done. Work transfers energy to objects.

What is a meniscus and why does it form when reading liquid measurements?

A meniscus is the curved surface of a liquid in a container. It can be: - Concave (curves down) - like water in glass - Convex (curves up) - like mercury It forms due to surface tension and adhesion between liquid and container. Always read at eye level at the bottom of the curve for accurate measurement.

How do you communicate scientific results and why is this step crucial?

Scientists communicate results by: 1. Writing research papers for scientific journals 2. Presenting at conferences 3. Sharing data with other researchers 4. Publishing findings for peer review This is crucial because it allows other scientists to verify, build upon, or challenge the results, advancing scientific knowledge.

A student wants to test if music affects plant growth. Design a proper controlled experiment including variables and procedure.

Independent Variable: Type of music (classical, rock, no music) Dependent Variable: Plant height/growth rate Controlled Variables: Same plant species, soil, water, light, temperature, pot size Procedure: 3 groups of identical plants, expose to different music conditions for set time daily, measure growth weekly, repeat multiple times, analyze data to draw conclusions.