Ch.5.1 Flashcards
All living things need _________________ to ______________ _________________ and _________________ ____________ ______________ _________________ ______________________.
Energy
Stay alive, carry out their daily activities
Animals and plants need energy to _________________. We also need energy to _________________ our _________________ and _________________.
Grow, power, appliances, machines
Energy is very _________________.
Important
Forms of energy: 1. 2. 3. 4. 5. 6. 7.
Sound energy, chemical energy, light energy, thermal energy, kinetic energy, potential energy, electrical energy
Sound energy is _________________ _____________ when an object _________________. A _________________ _________________ _________________ _________________ is an example of _________________ _________________.
Given out, vibrates, guitar string being plucked, sound energy
Chemical energy is stored in _________________, _________________ and _________________.
We need the chemical energy stored in _________________ to help us _________________ _________________, _________________ and _________________ _________________ _____________ ____________________.
When _________________ are _________________, chemical energy _________________ in them is _________________ as other forms of energy.
_________________ can provide energy for _________________ _________________ _________________ and other devices.
Food, fuels, batteries
Food, stay alive, grow, carry out our activities
Fuels, burned, stored, released
Batteries, small electrical appliances
The _________________ gives out light energy; some _________________ _________________ such as _________________ also give out light energy. _________________, _________________ and _________________ give out light energy too.
Light enables us to _________________ _________________.
Plants need light to _________________ _________________.
Sun, living things, fireflies, lamps, televisions, projectors, see things, make food
The _________________ gives out thermal energy.
_________________ _________________, _________________ _________________ and the _________________ of _____________ _________________ also give out thermal energy.
The _________________ an object, the _________________ thermal energy it gives out.
Sun, electric irons, electric heaters, flame, gas stoves, hotter, more
All _________________ _________________ have kinetic energy. The amount of kinetic energy of an object is related to its _________________ and _________________.
The _________________ an object moves, the _________________ kinetic energy it has.
The _______________ ___________ _________________ of a moving object, the _________________ kinetic energy it has.
Moving objects, mass, speed
Faster, more
Greater the mass, more
An object _________________ potential energy when it is _________________ to a _________________ _________________.
The _________________ the _________________ of the object, the _________________ potential energy it has.
Some objects also _____________ potential energy when they are _________________ or _________________.
_________________ rubber bands store _________________ energy than _________________ rubber bands.
Gains, raised, higher position
Higher, position, more
Store, compressed, stretched
Thicker, more, thinner
Electrical energy is the most ___________________ _____________ _______________ ____________ at ___________.
Electrical energy is usually _________________ from _________________ _________________ and then _________________ to our homes along _________________ _________________.
It can also be _________________ from _________________.
We can also observe the _________________ of electrical energy in _________________: eg _________________ and _________________ that can _________________ electrical energy to _________________ ______________________.
Widely used energy form, home
Supplied, power stations, transmitted, power cables
Obtained, batteries
Presence, Nature
Lightning, animals, generate, protect themselves
Energy can be measured in _________________ ______________: _________________, _________________, _________________, and _________________.
Different units
Joules, kilojoules, calories, kilocalories
We can measure energy in _________________ (J). One J represents a ____________ ______________ _______________ of energy.
We use _________________ (kJ) as the measuring unit for a _________________ _________________ of energy.
A _________________ (cal) is another unit of energy. This unit is commonly used for measuring the _________________ _________________ of _________________.
For a ____________ amount of energy, we use _________________ (kcal) as the unit.
joules, very small amount
kilojoules, larger amount
calorie, measuring, energy value, food
larger, kilocalories
1 kJ= _________________ J
1 kcal= _________________ cal
1 kcal= _________________ kJ (approx.)
1000, 1000, 4.18
