Dynamics and Space Flashcards
Define speed
The amount of distance covered per unit of time
What is the equation for speed?
V=d/t
Name the two different types of speed
Average and instantaneous
What is average speed?
Speed over a long distance
What is instantaneous speed?
Speed over a short distance
What is a scalar quantity?
One which has magnitude
Give an example of a scalar quantity
Speed
Mass
Distance
Time
What is a vector quantity?
One which has magnitude and direction
Give an example of a vector quantity
Velocity
Force
Displacement
Define distance
How far an object travels
Define displacement
How far an object is from it’s starting point
Name the two ways to calculate displacement
Scale diagram and trigonometry
How do you work out displacement?
Find how far the object has moved from the starting and in what direction
Define velocity
Speed of an object in a particular direction
What is the equation for velocity?
Velocity=displacement/time
What is acceleration?
The rate of change of velocity per unit of time
What is the equation for acceleration?
a= v - u / t
What is Newton’s first law?
An object will remain at rest or move at constant speed in a straight line unless acted on by an unbalanced force
What is a balanced force??
Forces that balance each other out in both directions
What is friction?
A force that tries to oppose the motion of an object - stop it from moving
What is Newton’s second law?
When an unbalanced force acts on an object the object will move with a constant acceleration in the direction of the unbalanced force
What is Newton’s equation for the second law?
F=ma
Define mass
The quantity of matter forming an object (kg)
Define weight
A force that depends on mass and location (N)
What is the equation for weight?
W=mg
Name some ways to reduce friction
Lubrication
Smoother surfaces
Stream lining
What is the equation for work done?
Ew=Fd
What is Newton’s third law?
Every action has an equal but opposite reaction
Define terminal velocity
When air resistance and weight balance out
Why do projectiles follow a curved path?
Gravity pulls them down and they have initial horizontal motion
What is the equation for horizontal motion?
d=vt
What is the equation for vertical motion?
v=u+at
How do you put an object into orbit?
Provide a high enough initial velocity to overcome gravity and the curvature of the earth
What is a geostationary satellite?
An earth orbiting satellite that revolves in the same direction as the earth rotates
What is a polar orbit satellite?
Satellite that passes above ore nearby both poles of the body being orbited, for example earth
What does our solar system consist of?
Planets, satellites, comets, asteroids and meteoroids
Name the two types of optical telescopes
Refracting and reflecting
What is the difference between the two telescopes?
Reflector telescopes use two mirrors instead of two lenses which refractor telescopes use
What are the advantages of earth based telescopes?
Easier to maintain
Lower cost
What are the advantages of space based telescopes?
Clearer shot of everything
Can observe near-infrared and ultraviolet light
Name some ways telescopes have changed our understanding of the universe
Shown us earth is not the centre of the universe
Allowed us to see mountains and craters on the moon
Reveals geography and weather on planets in this solar system
Revealed new planets and asteroids
Helped make first valid measurement of speed of light
How did scientists believe the universe began?
The shifting of the light to the red end of the spectrum implies the universe is expanding which means it must have started as a singularity
What is one light year?
The distance light travels in a year
What happens when light passes through a prism?
It splits into different colours of the spectrum
What is an absorption spectrum?
A spectrum of electromagnetic radiation transmitted through a substance showing dark lines due to absorption of specific wavelengths
What is the formula to calculate vertical velocity?
V = u + at
What is the formula to calculate horizontal velocity?
Vh = s/t
