Conduction, convection and radiation
Grade 8 Science Worksheet
Circle the best answer, or write your answer on the line.
A teacher's warm water cools from 80 °C to 60 °C in 10 minutes at a steady rate. How many degrees does it drop each minute, Ari?
A teacher's warm water cools from 70 °C to 52 °C in 6 minutes at a steady rate. How many degrees does it drop each minute, Bo?
Read this first
How well materials conduct heat (thermal conductivity, rounded; Data: Engineering ToolBox) (real data, rounded)
material conductivity (W/(m·K)) copper 400 steel 50 glass 1 wood 0.15 air 0.026 Jun picks a material for a pot handle that should stay cool. Use the table. Which is best?
- Wood
- Glass, since you can see through it
- Copper, since metal feels cool
- Steel, since it is strong
Double windows have a layer of air between two sheets of glass. Using the table, why does that help, Luz?
- Air conducts heat poorly
- The air layer makes warmth
- Glass conducts better than steel
- Air keeps out the cold
A heater sits on the floor of Milo's classroom, but the air near the ceiling is warmest. Why?
- The ceiling makes its own heat
- Radiation skips the floor
- Warm air rises and cooler air sinks
- Cold air flows down out of the ceiling
A teacher warms a beaker of water on a hot plate; a drop of food coloring swirls up and around. What path is this, Noah?
- Conduction
- Radiation from the coloring
- Convection
- Cold water pushing up from the bottom
On a sunny afternoon at the beach, a breeze blows from the sea toward the land. Why, Pia?
- The sand gives off wind
- Radiation pushes the air
- The sea pushes cold onto the land
- Warm air over the land rises, and sea air moves in
Ren learns that space between the Sun and Earth is almost empty. How does the Sun's energy reach Earth?
- By radiation
- By convection currents in space
- It can't cross empty space
- By conduction through space
Tala's family car is parked in the sun with the windows shut. The dark seat gets hot. How did the energy arrive?
- Convection from the engine
- Radiation from the Sun
- Conduction from the warm air outside
- Cold leaving the seat
Zee lays a black shirt and a white shirt in the sun. Why does the black one warm faster?
- It absorbs more radiation
- It conducts warmth from the air
- It makes its own heat
- It keeps the cold out