🗂️ Science Word Problems for K-8

A plant grows 2 cm each week. How tall will it be after 5 weeks if it starts at 10 cm?

A pendulum swings 20 times in 30 seconds. How many swings in 2 minutes?

A solution is 15% salt. If you have 200 grams of solution, how many grams of salt does it contain?

Sound travels at 340 m/s. If you hear thunder 5 seconds after seeing lightning, how far away is the storm?

A science experiment uses 250 mL of water 3 times. How much water is used in total?

An object accelerates from 10 m/s to 30 m/s in 5 seconds. What is the acceleration? (a = change in velocity ÷ time)

Light travels at 300,000 km/s. How far does it travel in 5 seconds?

A gas occupies 500 mL at 20°C. If heated to 40°C (keeping pressure constant), it expands to 550 mL. By what percentage did the volume increase?

A circuit has a 9V battery and 3Ω resistor. What is the current? (Ohm's Law: V = IR)

A magnifying glass has a magnification of 4x. If an ant is actually 5 mm long, how long does it appear?

A 2 kg object is moving at 5 m/s. What is its kinetic energy? (KE = ½mv²)

The moon orbits Earth at 380,000 km distance. Light travels at 300,000 km/s. How long does light from the moon take to reach Earth?

A gene has 1200 base pairs. How many amino acids does it code for? (3 base pairs = 1 amino acid)

The Earth's radius is 6,400 km. What is its circumference? (C = 2πr, π ≈ 3.14)

Water has a heat capacity of 4.18 J/g°C. How much energy is needed to heat 500g of water by 20°C?

A pulley system has a mechanical advantage of 4. If you pull with 20 N of force, how much weight can you lift?

A car engine is 25% efficient. If it uses 2000 joules of energy from fuel, how much useful work does it produce?

A rock falls from a 45-meter cliff. If it accelerates at 10 m/s², how fast is it going after 3 seconds? (v = at)

Water freezes at 0°C. If the temperature is 5°C and drops 8°, what is the new temperature?

A spring stretches 8 cm when a 4 N force is applied. How far will it stretch with a 6 N force? (Hooke's Law: F = kx)

The half-life of a substance is 10 days. If you start with 800 grams, how much remains after 20 days?

A lever is 2 m long. The fulcrum is 0.5 m from the load. If you push down with 50 N on the long end, what force is applied to the load?

An ecosystem has 10,000 units of energy at the producer level. If each trophic level transfers 10%, how much energy reaches the secondary consumers?

A population of 500 bacteria doubles every 30 minutes. How many bacteria are there after 2 hours?

A prism bends light by 30°. If light enters at 60° to the normal, what angle does it exit at?

A DNA strand is 30% adenine. What percentage is guanine? (In DNA: A=T and G=C)

A microscope magnifies 400x. A cell appears to be 8 mm wide. What is its actual width in micrometers? (1 mm = 1000 μm)

A science experiment uses 250 mL of water 3 times. How much water is used in total?

Light travels at 300,000 km/s. How far does it travel in 5 seconds?

A gas occupies 500 mL at 20°C. If heated to 40°C (keeping pressure constant), it expands to 550 mL. By what percentage did the volume increase?

Water freezes at 0°C. If the temperature is 5°C and drops 8°, what is the new temperature?

A plant grows 2 cm each week. How tall will it be after 5 weeks if it starts at 10 cm?

A pendulum swings 20 times in 30 seconds. How many swings in 2 minutes?

A substance has a density of 2.5 g/cm³. What is the mass of 8 cm³ of this substance?

A solution is 15% salt. If you have 200 grams of solution, how many grams of salt does it contain?

A science experiment uses 250 mL of water 3 times. How much water is used in total?

An object accelerates from 10 m/s to 30 m/s in 5 seconds. What is the acceleration? (a = change in velocity ÷ time)

Light travels at 300,000 km/s. How far does it travel in 5 seconds?

A gas occupies 500 mL at 20°C. If heated to 40°C (keeping pressure constant), it expands to 550 mL. By what percentage did the volume increase?

A thermometer shows 72°F. What is this temperature in Celsius? (C = (F - 32) × 5/9)

A plant is 15 cm tall and grows 0.5 cm per day. How tall will it be after 10 days?

A battery has 2500 mAh capacity. A device uses 100 mAh per hour. How long will the battery last?

A test tube contains 30 mL of solution. How many microliters is that? (1 mL = 1000 μL)

Water boils at 100°C. If the current temperature is 25°C, how much hotter does it need to be?

A recipe has 1000 calories total. If it makes 4 servings, how many calories per serving?

A bacteria population doubles every 2 hours. Starting with 100 bacteria, how many will there be after 6 hours?

A light bulb uses 60 watts. If it runs 4 hours per day, how many watt-hours per day?

A cube has sides of 4 cm. What is its volume?

A container has 4 liters of liquid. After evaporation, only 3 liters remain. What percentage evaporated?

A chemical reaction requires 3 parts A to 5 parts B. If you have 30 units of A, how much B do you need?

An object weighs 10 kg on Earth. What would it weigh on the Moon (1/6 of Earth's gravity)?

A car engine produces 200 horsepower. If 1 horsepower = 746 watts, how many watts is that?

A radioactive substance has a half-life of 5 years. If you start with 80 grams, how much remains after 15 years?

A river flows at 3 meters per second. How far does the water travel in 1 hour?

A plant needs 500 mL of water daily. How much water does it need in a month (30 days)?

A thermometer reads 95°F. How many degrees below boiling point (212°F)?

A chemical mixture is 40% acid. If you have 500 mL of the mixture, how much pure acid is in it? Then, if you add 100 mL of pure acid, what is the new percentage?

A population of bacteria starts with 1000 cells and triples every hour. How many bacteria will there be after 5 hours?

A radioactive element has a half-life of 8 days. If you start with 640 grams, how much remains after 32 days?

A solution contains 250 mL of water and 50 mL of salt. If you add 150 mL more water, what is the new concentration of salt as a percentage?

A pendulum swings with a period of 2 seconds. How many complete swings will it make in 1 minute?

A plant grows 0.5 inches per week. How many inches will it grow in 8 weeks?

A scientist measures a sample that weighs 0.025 grams. If they need 8 samples, what is the total weight?