Physics: Final Exam Flashcards
What does the Solar System consist of? (hint: 5 main things)
- The Sun
- 8 planets
- Natural and artificial satellites
- Dwarf planet
- Asteroids and comets
What are the rocky planets? (hint: 4)
- Mercury
- Venus
- Earth
- Mars
What are the gas planets? (hint:4)
- Jupiter
- Saturn
- Uranus
- Neptune
What planet is the dwarf planet?
Pluto
What are some characteristics of the sun?
- The Sun lies at the centre of the Solar System
- The Sun is a star that makes up over 99% of the mass of the Solar System
How strong are gravitational fields?
- Around planets is strong enough to have pulled in all nearby objects except for natural satellites
- Around a dwarf planet is not strong enough to have pulled nearby objects
What are the two types of satellites?
- Natural
- Artificial
What is an example of a natural satellite?
- Some planets have moons orbiting them
- Moons are an example of natural satellites
What are artificial satellites?
Artificial satellites are man-made and can orbit any object in space
What is an asteroid?
An asteroid is a small rocky object which orbits the sun
What is a comet?
Comets are made of dust and ice and orbit the Sun in a different orbit to the planets
Exam Tip:
My Very Easy Method Just Speeds Up Naming (Planets) =
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, (Pluto)
What is the definition for Weight?
The force acting on an object due to gravitational attraction
What does weight do?
- Objects stay firmly on the ground
- Objects will always fall to the ground
- Satellites are kept in orbit
How are objects attracted to the centre of the Earth?
-Due to its gravitational field strength
How does mass affect a planet?
The greater the mass of the planet, the stronger the gravitational field strength is going to be
How much gravitational field strength (g) does the Earth have?
Approximately 10 N/kg
What does gravity provide?
Provides a force which pulls an object towards a body
How are the sun’s rays acting in summer and winter?
- summer: The sun’s rays are concentrated
- winter: The sun’s rays are spread out
When is it summer and winter in Europe?
summer: When the nothern hemisphere is tilted towards the sun
winter: When the northen hemisphere is titled away from the sun
Why are days longer than nights in summer?
As the earth is tilted towards the sun, we get more sunlight, making the day longer.
What is a magnetic field?
The region around a magnet where a force acts on another magnet or on a magnetic material (iron, steel, cobalt and nickel)
Is the magnetic field stronger in the pole or south?
POLE
What is Friction?
force when an object is being pulled along the ground
How can friction be reduced?
Through wheels or rollers
What is the resultant force?
The difference between the forwards and backwards forces.
What can unbalanced forces do?
They can change the speed of an object and the direction
What are the 2 forms of drag?
Water resistance and air resistance
What does drag do?
Slows down objects moving through fluids.
What affects the drag?
- The speed (drag force increases and speed increases)
- Surface area
What is the top speed?
- When the resistance (drag) is as large as the force
- This means the object can’t accelerate.
Where does the energy from humans and animals come from?
Food
What is kinetic energy?
Anything that is moving.
What is speed?
How fast or slow something is
What is the formula for Speed?
Speed= Distance (in a graph = rise/run)
—————
Time
What is velocity?
It is a vector quantity which decribes both magnitude and direction
What is the formula for Velocity?
Time
What is acceleration?
rate of change of velocity
What is the formula for acceleration?
time taken
What is the formula for the change in velocity?
final velocity - initial velocity
What does a distance time graph show?
shows how the distance of an object moving in a straight line (from a starting position) varies over time
What does a velocity graph show?
shows how the velocity of a moving object varies with time
What is an electrostatic force?
-the force between two charged objects
What is thrust?
-the force causing an object to move
What is upthrust?
-the force of a fluid pushing an object upwards
What is compression?
-forces that act inward on an object, squeezing it
What is a reaction force (or normal force)?
-a force due to contact between two objects
What is a contact force?
A force which acts between objects that are physically touching
What are examples of contact forces?
- Friction
- Air Resistance
- Tension
- Reaction force/normal force
What is a non-contact force?
- A force which acts at a distance
- No contact between bodies
- Due to the action of a field
What are examples of non-contact forces?
- Gravitational force
- Electrostatic force
- Magnetic force
What causes the seasons?
This happens because the Earth’s axis is tilted
.
What is the formula for weight?
Newtons (N)
What is the formula for mass?
Kilograms (Kg)
What is the formula for mass?
Kilograms (Kg)
What is the formula gravitational field strength?
Newtons/Kilograms (N/Kg)
How do you calculate the mass on a planet?
Calculate the weight of a 5kg mass on Earth:
weight= mass x g
=5 x 10
=50
What is the definition for Force?
a push or pull on an object that produces acceleration in the body on which it acts
What is the definition for Mass?
How much matter something is made of
