A mindennapi dolgok tudománya

by Vocafy Ellenőrzött

Angol (US) B1 15 kérdés Science

Fedezd fel, miért olvad a jég, miért nőnek az árnyékok, és miért viselkednek meglepő módon a hétköznapi tárgyak.

1. 1. Válaszd ki a helyes választ.

   Miért válik folyékonnyá a jég?

   An ice cube is left on a plate in a warm kitchen. Slowly, it melts.

   • It absorbs heat from the room.
   • It releases heat into the room.
   • The room air presses it into a liquid.

   Gondold végig, melyik melegebb: a jég vagy a szoba.

   Show solution

   • It absorbs heat from the room.

   A hő a melegebb testektől a hidegebbek felé áramlik. Még a szoba hűvös levegője is elég meleg lehet ahhoz, hogy megolvassza a jeget.

2. 2. Töltsd ki az üres helyet.

   A ball rolls across a level carpet. It slows down because ___ acts against its movement.

   • gravity
   • friction
   • magnetism

   Think about the contact between the ball and the carpet.

   Show solution

   A ball rolls across a level carpet. It slows down because friction acts against its movement.

   Friction resists movement between touching surfaces. Some of the energy from the ball's movement becomes heat.

3. 3. Válaszd ki a helyes választ.

   Miért láthatod az arcodat a tükörben?

   You stand in front of a mirror in a bright room.

   • It makes its own light in the shape of your face.
   • It pulls light from your eyes toward your face.
   • It sends light from your face back to your eyes.

   A tükör megváltoztatja a fény irányát.

   Show solution

   • It sends light from your face back to your eyes.

   A tükör visszaveri a fényt. Sima felületének köszönhetően a visszavert fény rendezett marad, ezért éles képet látsz.

4. 4. Válaszd ki a helyes választ.

   Mi hozza létre a hangot?

   You pull a guitar string to one side and let it go. You hear a musical note.

   • The string heats the air as it moves.
   • The string vibrates and makes the air vibrate.
   • The string sends light waves through the air.

   Figyeld meg, hogyan mozog a húr, miután elengeded.

   Show solution

   • The string vibrates and makes the air vibrate.

   A hang rezgések formájában terjed a levegőben. A gitár teste is rezeg, így felerősíti a hangot.

5. 5. Töltsd ki az üres helyet.

   Cooking oil and water are at the same temperature. The oil floats on top because it is ___.

   • more dense than water
   • as dense as water
   • less dense than water

   Hasonlítsd össze az azonos térfogatú olaj és víz súlyát.

   Show solution

   Cooking oil and water are at the same temperature. The oil floats on top because it is less dense than water.

   A sűrűség a tömeget a térfogathoz viszonyítja. Egy csésze étolaj súlya kisebb, mint egy csésze vízé.

6. 6. Válaszd ki a helyes választ.

   Why is your shadow longer in the late afternoon?

   On level ground, your shadow is usually longer in the late afternoon than around noon.

   • The Sun is lower in the sky.
   • The Sun is higher in the sky.
   • The Sun is much closer to Earth.

   Think about the angle at which sunlight reaches the ground.

   Show solution

   • The Sun is lower in the sky.

   Light from a low Sun reaches the ground at a smaller angle, stretching shadows farther across it.

7. 7. Válaszd ki a helyes választ.

   Honnan származik a külső felületen lévő víz?

   A dry, unbroken glass is filled with ice water. Soon, drops form on the outside. No water has spilled.

   • Water inside passes through the glass.
   • Water in the air cools and becomes liquid.
   • The ice pushes water over the top.

   A levegő akkor is tartalmaz vizet, ha nem látod.

   Show solution

   • Water in the air cools and becomes liquid.

   Ezt a változást páralecsapódásnak nevezzük. Ez okozza a forró zuhany után a fürdőszobai tükrön megjelenő vízcseppeket is.

8. 8. Töltsd ki az üres helyet.

   Two shirts are made of the same fabric and have the same thickness. In direct sunlight, the black shirt usually gets hotter because it ___.

   • reflects more of the sunlight
   • absorbs none of the sunlight
   • absorbs more of the sunlight

   Think about whether the light bounces away or enters the material.

   Show solution

   Two shirts are made of the same fabric and have the same thickness. In direct sunlight, the black shirt usually gets hotter because it absorbs more of the sunlight.

   Absorbed sunlight adds heat to the fabric. White surfaces reflect more sunlight, which can help them stay cooler.

9. 9. Válaszd ki a helyes választ.

   Mi húzza a hajat a léggömb felé?

   You rub a balloon against a sweater. When you hold it near your hair, some hairs rise toward it.

   • An electric force.
   • A magnetic force.
   • Extra air pressure.

   Dörzsölés hatására apró, elektromos töltésű részecskék kerülhetnek át egyik anyagból a másikba.

   Show solution

   • An electric force.

   A dörzsölés elektromos töltést ad a léggömbnek. A léggömb apró papírdarabokat is magához vonzhat, még akkor is, ha azok nem fémből vannak.

10. 10. Válaszd ki a helyes választ.

    Why does your skin feel cooler as your hands dry?

    Your hands are wet. As they dry in the air, your skin feels cool.

    • The water gives extra heat to your skin.
    • The water becomes tiny pieces of ice.
    • The water takes heat from your skin as it becomes a gas.

    Changing liquid water into a gas requires energy.

    Show solution

    • The water takes heat from your skin as it becomes a gas.

    This process is called evaporation. Sweat cools your body in the same way when it evaporates.

11. 11. Válaszd ki a helyes választ.

    Miért könnyítheti meg a fedél felmelegítése az üveg kinyitását?

    A metal lid is stuck on a glass jar. You run warm water over the lid.

    • The metal lid becomes lighter.
    • The metal lid expands a little.
    • The metal lid shrinks a little.

    Gondolj arra, hogyan változik a fém mérete, amikor felmelegszik.

    Show solution

    • The metal lid expands a little.

    A legtöbb fém melegítés hatására kitágul. A fedél szélességének már kismértékű növekedése is elég lehet ahhoz, hogy kevésbé szoruljon az üvegre.

12. 12. Válaszd ki a helyes választ.

    Hogyan segít a bezárt levegő melegen tartani a forró italt?

    A cup has two walls with still air trapped between them.

    • The air slows the movement of heat out of the cup.
    • The air produces new heat inside the cup.
    • The air carries heat quickly through the walls.

    A nyugvó levegő nem vezeti jól a hőt.

    Show solution

    • The air slows the movement of heat out of the cup.

    A bezárt levegő hőszigetelést biztosít: lassítja a hőveszteséget. Sok meleg kabát is levegőt zár a szálai közé.

13. 13. Töltsd ki az üres helyet.

    Two backpacks weigh the same, but one has wider shoulder straps. The wider straps can feel more comfortable because they spread the weight over ___.

    • a smaller area of your shoulders
    • the same area of your shoulders
    • a larger area of your shoulders

    Compare how a thin string and a wide belt press against your hand.

    Show solution

    Two backpacks weigh the same, but one has wider shoulder straps. The wider straps can feel more comfortable because they spread the weight over a larger area of your shoulders.

    The same force spread over a larger area creates less pressure. Wider straps reduce pressure without reducing the backpack's weight.

14. 14. Válaszd ki a helyes választ.

    Why can potatoes take longer to cook in boiling water there?

    High in the mountains, water boils at a lower temperature than it does at sea level.

    • Water stops transferring heat once it boils.
    • The water is cooler, even while it is boiling.
    • The bubbles in the boiling water prevent heat from reaching the potatoes.

    Boiling water is not always at the same temperature.

    Show solution

    • The water is cooler, even while it is boiling.

    Lower air pressure allows water to boil at a lower temperature. Food can therefore cook more slowly, even with plenty of bubbles.

15. 15. Válaszd ki a helyes választ.

    What makes the bottle's sides bend inward?

    A thin plastic bottle full of warm air is tightly closed. As it cools in a cold room, its sides bend inward.

    • The air inside pushes harder than the air outside.
    • The air pressure is equal inside and outside.
    • The air outside pushes harder than the air inside.

    The bottle is closed, so no more air can enter as the trapped air cools.

    Show solution

    • The air outside pushes harder than the air inside.

    Cooling lowers the pressure of the trapped air. Outside air then pushes the flexible sides inward.