Unit 1 - Our Dinamic Universe Flashcards
(49 cards)
How do you calculate
“Absolute Random Uncertainty”
(Largest Value - Smallest Value) / Number of Values
What is the accuracy of a analogue scale ?
Can be read to an accuracy of HALF the smallest scale division
What is the accuracy of a Digital scale ?
Can be read to an accuracy EQUAL to the smallest scale division
How do you combine uncertainties ?
- Calculate any random uncertainty
- Calculate the percentage uncertainty in all quantities
- Find the percentage uncertainty with the highest value, I.e. Worst uncertainty
- Calculate the absolute uncertainty in the result using the worst uncertainty chosen in 3.
What is a projectile ?
“A projectile is an object which travels with both horizontal and vertical components under the influence of Gravity”
What calculation would you do for each Horizontal and Vertical components of a projectile ?
Horizontal -> Speed = Distance x Time
Vertical -> U.V.A.S.T
V.U.A.S.T
What are the 3 graphs of projectiles that are in higher ?
Displacement / Time
Velocity / Time
Acceleration / Time
Which one of Newtons laws has an equation and what is the law ?
Newton II
F = ma
“If a mass is acted upon by an unbalanced force it will cause it to accelerate
What does a force of 1N cause on a mass of 1kg ?
A force of 1N can cause a mass of 1kg to accelerate at 1m/s
What is “Terminal Velocity” ?
Terminal Velocity is the maximum velocity you can travel while “falling”
Skydiving:
When you are in free fall, you will begin to accelerate as your weight is great than the air resistance acting against you, however eventually the air resistance will be equal to your weight, so you won’t accelerate anymore as the forces acting on you are balanced
What is “Apparent Weight” ?
“Apparent Weight”
Is the reading on (e.g. Scales) when there is an upwards force acting on you
If there is an upwards force greater than your weight, your apparent weight will be greater than your weight,
if the upwards force is less than your weight, your apparent weight will be less than your weight
How do you calculate “Weight Down a slope”
Competent acting parallel to the slope -> Mg x Sinx
Components acting perpendicular to the slope -> Mg x Cosx
What is momentum ?
Momentum is the product of
mass x Velocity
What is the Law of Conservation of Linear Momentum ?
The momentum before a Collision is Equal to the momentum after
In the Absence of any External Forces
What happens to kinetic Energy if there is an Elastic Collision ?
When there is an Elastic Collision, kinetic energy is conserved
What happens to Kinetic energy when a collision is Inelastic ?
When a Collision is Inelastic, Kinetic Energy is not conserved, lost.
During an Explosion, Kinetic Energy is gained.
What is Impulse ?
Impulse is equal to the change in an objects momentum
How would you calculate impulse (I.e. change in Momentum) ?
- Ft = Mv - Mu
2. Area under a Ft graph(A=1/2 bh)
What does Newtons Law of Gravitation state ?
“The Gravitational attraction between 2 objects is directly proportional to the mass of each object and is inversely proportional to the square of their distance apart”
What is the formula for Newtons Law of Gravitation ?
F = G x (mass1) x (mass2)
———————-
distance^2
“Big G” x both mass of each object,
divided by the distance squared
What is ‘Time Dilation” ?
Time Dilation is:
When an observer observes an event where an object is travelling close to the speed of light in their own reference frame either moving relative to the event or stationary and there is a difference of elapsed time between both frames of reference.
What is “Length Contraction?”
Length Contraction is:
When an observer observes an object travelling close to the speed of light in their own reference frame and measures a decrease in length of an object
What is the Doppler Effect ?
The Doppler Effect artists from a source of waves having a velocity relative to the observer
How do you know which frequency equation to use when calculating observed frequency ?
When the object is moving away from an observer we use ( V + Vs )
When the object is moving towards an observer we use ( V - Vs )
