Year 8 Science – Change: Energy Transformations 1
Practise identifying energy stores and transformations, heat transfer, conservation of energy and reading investigation data. 20 questions. 25 minutes.
An archer pulls the string of a bow back and holds it, ready to fire. Which store holds the energy in the bow?
A hiker cracks open a hand warmer and it slowly becomes warm. Which energy change happens?
Choose the word that completes each blank.
A boulder resting at the top of a cliff has 1 energy. When it rolls down the slope it gains 2 energy.
Blank 1: gravitational potential · kinetic · thermal
Blank 2: elastic potential · chemical · kinetic
Choose the word that completes the blank.
On a hot day, warm air over the land rises and cooler air from the ocean moves in to replace it. This movement of energy is 1.
Blank 1: radiation · convection · conduction
Circle 1 word in the sentence below.
In a lava lamp, wax heated at the bottom rises, cools near the top and sinks again. Click the way the energy is transferred.
conductionconvectionradiation
A child winds up a toy car, puts it on the floor and lets go. Which energy change makes the car move?
Three identical cans were filled with 200 mL of water at 20 °C and placed 30 cm from the same heater. Which can absorbed radiation best?
| Surface | Temperature rise after 10 minutes (°C) |
|---|---|
| Shiny silver | 4 |
| Matte black | 12 |
| White | 6 |
The inside of a parked car gets very hot as sunshine comes through the windows. How does energy travel from the Sun to the car?
Choose the words that complete each blank.
A runner's muscles change 1 energy from food into 2 energy and some thermal energy.
Blank 1: elastic · light · chemical
Blank 2: sound · kinetic · electrical
Choose the word that completes the blank.
A lit campfire gives out smoke and heat, so it is a(n) 1 system.
Blank 1: open · closed · isolated
Circle 2 words in the sentence below.
Click the two words that name the object storing energy.
astretchedslingshotafallingappleahotcup
Choose the word that completes the blank.
In a solar-powered calculator, the solar cell changes light energy into 1 energy.
Blank 1: thermal · electrical · chemical
Circle 2 words in the sentence below.
Click the two forms of energy that come OUT of the globe.
Anincandescentglobechangeselectricalenergyintolightandthermalenergy
A solar garden light charges its rechargeable battery all day and glows at night. Which store holds the energy overnight?
In a chain machine, a toy car rolls down a ramp and hits a wooden block at the bottom, pushing it along. Which statement describes the collision?
Choose the word that completes the blank.
An electric kettle takes in 2000 J of electrical energy and gives 1800 J to the water. The remaining energy is not destroyed; it spreads out as 1 energy in the surroundings.
Blank 1: thermal · chemical · gravitational
A motor takes in 250 J of electrical energy each second and gives out 180 J of useful kinetic energy. How much energy becomes thermal energy (and sound) each second?
A pendulum bob has 8 J of gravitational potential energy at the top of its swing. Ignoring friction, how much kinetic energy does it have at the bottom of the swing?
A student drops the same ball from different heights onto a hard floor. Which conclusion fits the data?
| Drop height (cm) | Bounce height (cm) |
|---|---|
| 20 | 14 |
| 40 | 28 |
| 60 | 42 |
A student compares the bounce of a tennis ball on carpet with a basketball on tiles, both dropped from 1 m. Which change would make this a fair test?