ScienceYear 10

Year 10 Science – Change: Energy Transformations 1

Practise evaluating energy claims, comparing heat transfers in designs, calculating efficiency and analysing investigation data. 20 questions. 25 minutes.

Crate A (2 kg) and crate B (4 kg) are each lifted onto the same shelf. Which statement compares the gravitational PE they store?

Crate A stores twice as much as crate BCrate B stores four times as much as crate ACrate B stores twice as much as crate ABoth crates store the same amount

The air has been removed from the gap between the two walls of a thermos flask. Which heat transfers does this empty gap stop?

Conduction and convectionConvection and radiationRadiation onlyConduction only

Choose the words that complete each blank.

When a rechargeable battery is charged, electrical energy is transformed into ₁ energy. When the battery later runs a motor, that energy ends up as ₂ energy and some thermal energy.

Blank 1: elastic · gravitational · thermal · chemical

Blank 2: chemical · kinetic · light

Circle 2 words in the sentence below.

Click the two situations where convection is the main way energy is transferred.

Hot-air-balloonHeat-lampIron-pokerSimmering-soupSunlight-on-skin

A 2 kg mass lifted 1.5 m stores 30 J of gravitational PE. How much would the same mass store when lifted 4.5 m?

45 J90 J33 J120 J

A sealed glass jar of hot water sits in a sunny window. Which classification of the jar and its contents is correct?

Isolated, because the lid keeps all the matter insideOpen, because energy is crossing the boundaryClosed, because no energy can cross the glassClosed, because energy crosses the glass but matter cannot

Choose the word that completes the blank.

The Earth receives sunlight and radiates thermal energy back to space, but almost no matter crosses its boundary. For matter and energy together, the Earth is best described as a ₁ system.

Blank 1: closed · open · isolated

In a rooftop solar hot-water panel, black pipes absorb sunlight and the water warmed in them rises to a tank above. Which list shows the transfers in the correct order, from the Sun to the water in the tank?

Radiation, convection, conductionRadiation, conduction, convectionConduction, radiation, convectionConvection, conduction, radiation

Choose the words that complete each blank.

A machine's wasted energy is not destroyed; it is ₁ into the surroundings as thermal energy. The total energy after is therefore ₂ the total energy before.

Blank 1: destroyed · created · dissipated

Blank 2: less than · equal to · greater than

10.

A ball has 0.50 J of gravitational PE when released and rebounds to a height where it has 0.30 J. A student claims the missing 0.20 J was destroyed on impact. Which evaluation is correct?

The claim is wrong: the 0.20 J became thermal and sound energy in the floor and airThe claim is right: the 0.20 J was used up and no longer existsThe claim is wrong: the 0.20 J is now kinetic energy the ball keepsThe claim is right: energy is only conserved while the ball is in the air

11.

Circle 1 word in the sentence below.

A student writes: 'The motor wastes 30 J each second, and this energy is destroyed.' Click the word that makes the statement wrong.

Themotorwastes30Jeachsecond,andthisenergyisdestroyed.

12.

Choose the words that complete each blank.

A solar hot-water panel changes light energy from the Sun into ₁ energy, while a photovoltaic solar panel changes it into ₂ energy.

Blank 1: chemical · kinetic · thermal

Blank 2: electrical · thermal · chemical

13.

A company advertises a motor that takes in 500 J of electrical energy each second and delivers 600 J of useful kinetic energy. Which evaluation is correct?

Possible: the efficiency would be 120%, which is excellentImpossible: a motor must waste at least half of its inputImpossible: that would create 100 J of energyPossible: the extra 100 J comes from the motor's sound energy

14.

Lamp A takes in 50 J and gives out 10 J of light. Lamp B takes in 20 J and gives out 8 J of light. The rest is thermal energy. Which lamp is more efficient?

Lamp A, with 10 J of light against 8 JLamp B, with 40% against 20%Lamp A, with 40 J of thermal energy against 12 JNeither, because energy is conserved in both

15.

Choose the numbers that complete each blank.

A device takes in 400 J and gives out 100 J of useful energy. Its efficiency is ₁%, so ₂ J is dissipated as thermal energy.

Blank 1: 75 · 25 · 4

Blank 2: 300 · 500 · 100

16.

A student dropped a ball from 1.0 m onto four surfaces. The heights were judged by eye beside a ruler. Which change would most improve the accuracy of the rebound heights?

Surface	Mean rebound height (cm)
Tile	62
Wood	55
Carpet	31
Sand	8

Film each bounce beside a ruler and read the peak frame by frameDrop the ball from 2.0 m instead of 1.0 m each timeUse a different ball for each surface to avoid wearDrop the ball once on each surface and record the highest

17.

Choose the words that complete each blank.

Judging a rebound height by eye is a source of ₁ error. This is reduced by repeating each trial and calculating the ₂.

Blank 1: conservation · calculation · measurement

Blank 2: mean · total · maximum

18.

Circle 2 words in the sentence below.

Click the two parts of a chain machine that store elastic PE before they are released.

Stretched-bandRolling-marbleCompressed-springFalling-dominoHot-motor

19.

A pendulum bob swings from a high release point. Which statement best explains the data?

Position	GPE (J)	KE (J)
Top	6.0	0.0
Middle	3.0	2.8
Bottom	0.0	5.5

The total falls because KE is always smaller than GPEThe total stays at 6.0 J, so the readings must be wrongThe total falls because 0.5 J was destroyed by frictionThe total falls because 0.5 J became thermal energy in the air and pivot

20.

In a chain machine, falling dominoes release 2.0 J of gravitational PE. The car at the ramp base has 1.4 J of KE. The block has 0.5 J of KE after the collision. Between which stages was the most energy dissipated?

From the dominoes to the car at the ramp baseNone: energy is only dissipated after the block stopsFrom the car to the block after the collisionThey are equal because energy is conserved

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Year 10 Science – Change: Energy Transformations 1