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Science Principles of Forces Energy and Matter
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Science Principles of Forces Energy and Matter
Science Principles of Forces Energy and Matter
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1
Question
Why is it harder to stop larger and faster moving objects according to the notes?
Page 2
Answer
Larger and faster objects have more momentum, making it more difficult to stop them or change their direction.
2
Question
What are forces defined as in the context of Big Idea 1?
Page 2
Answer
Forces are pushes or pulls that are measured in Newtons (N).
3
Question
What effects can forces have on an object?
Page 2
Answer
Forces can change an object's speed, direction, or shape and are required to start or stop movement.
4
Question
How do contact forces differ from non-contact forces?
Page 2
Answer
Contact forces require contact between objects, like upthrust, friction, air, and water resistance; non-contact forces act at a distance, like magnetism, static, and weight.
5
Question
How are forces represented on a diagram?
Page 2
Answer
Arrows represent forces, with arrow size showing force magnitude and direction showing force direction.
6
Question
What instrument measures the size of a force?
Page 2
Answer
A Newton meter measures the size of a force.
7
Question
What causes friction and how can it be reduced?
Page 2
Answer
Friction is caused by microscopic bumps in surfaces; it can be reduced using a lubricant such as oil.
8
Question
In what directions do forces always act according to the notes?
Page 2
Answer
Forces always act in pairs in opposite directions to each other.
9
Question
What distinguishes balanced forces from unbalanced forces?
Page 2
Answer
Balanced forces are the same size; unbalanced forces are different sizes.
10
Question
What is the formula for resultant force when two forces act in opposite directions?
Page 2
Answer
Resultant force = larger force - smaller force.
11
Question
If two forces of 300 N and 100 N act in opposite directions, what is the resultant force?
Page 2
Answer
Resultant force = 300 N - 100 N = 200 N in the direction of the larger force.
12
Question
How does resultant force affect an object if forces are unbalanced?
Page 2
Answer
Unbalanced forces cause the object to change speed, direction, or shape.
13
Question
What happens to an object when forces acting on it are balanced?
Page 2
Answer
The object is either stationary or moving at a constant speed.
14
Question
What are the five main stores of energy listed in the notes?
Page 3
Answer
Kinetic, chemical, thermal, gravitational, and elastic stores.
15
Question
What is the kinetic store of energy?
Page 3
Answer
Energy contained in moving objects.
16
Question
Give examples of energy transfers between stores from the notes.
Page 3
Answer
Wind-up toy: elastic to kinetic; battery fan: chemical to kinetic; ball down slope: gravitational to kinetic; hot water: thermal to surroundings.
17
Question
What unit measures energy in stores and what conversion is given?
Page 3
Answer
Joules (J); 1 kilojoule (kJ) = 1000 J.
18
Question
How is the energy content of food measured experimentally?
Page 3
Answer
Burn food to heat a set volume of water and measure temperature increase with a thermometer.
19
Question
What is the formula for work done and its units?
Page 3
Answer
Work done (J) = Force (N) × Distance (m).
20
Question
How does stretching or compressing a spring transfer energy?
Page 3
Answer
Work done increases the elastic energy store; bigger force causes more stretch and more work.
21
Question
What are fossil fuels and why are they non-renewable?
Page 3
Answer
Coal, crude oil, natural gas; used faster than they can be made, risking depletion.
22
Question
What are the steps in generating electricity at a power station?
Page 3
Answer
1. Fuel burns to heat water. 2. Steam created. 3. Steam turns turbine. 4. Generator produces electricity.
23
Question
What is power rating for appliances and its formula?
Page 3
Answer
Power in Watts (W) measures energy transferred per second; Energy (J) = Power (W) × time (s).
24
Question
Name four renewable energy resources and one advantage and disadvantage each.
Page 3
Answer
Wind (no pollutants, noisy/unsightly); Solar (no pollutants, unreliable/expensive); Hydroelectric (no pollutants, expensive dams/flooding); Biomass (requires land).
25
Question
What are physical properties of metals listed in the notes?
Page 4
Answer
Shiny, hard, malleable, conductors of heat and electricity, density.
26
Question
What are two main types of non-metal matter and their key properties?
Page 4
Answer
Ceramics (from clay, hardened by heat, hard, brittle, poor conductors); Polymers (man-made from crude oil, strong, poor conductors of heat/electricity).
27
Question
What defines composite materials?
Page 4
Answer
Materials made from more than one type, designed for specific purposes taking properties from components.
28
Question
List the properties of solids and liquids from the particle model.
Page 4
Answer
Solids: fixed shape, cannot flow, cannot be compressed. Liquids: take container shape, can flow, difficult to compress.
29
Question
Describe particle arrangement in solids according to the particle model.
Page 4
Answer
Regular pattern, tightly packed, vibrate in fixed positions with strong non-contact attraction forces.
30
Question
What happens to particles when a solid melts into a liquid?
Page 4
Answer
Particles lose regular pattern, still touching but move over each other.