Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

SMHS Higher Physics > Our Dynamic Universe > Flashcards

Our Dynamic Universe Flashcards

You may prefer our related Brainscape-certified flashcards:
Physics 101 flashcards AP® Physics flashcards
1
Q

Explain the equation Ft = mv - mu

A

Ft is the impulse

mv – mu is the change in momentum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the law of conservation of momentum

A

In the absence of external
forces the total momentum before a collision equals the total momentum after a collision.
m1u1 + m2u2 = m1v1 + m2v2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q 
Recognise the
formulae for work
done, kinetic energy,
gravitational potential
energy and power
A

Ew = Fd

Ek =1⁄2mv2 Ep = mgh P = E/t

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe why projectiles follow a curved path

A

They have a constant horizontal velocity (ignoring air resistance) and a constant vertical acceleration due to the force of gravity (weight)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How do you calculate the horizontal and vertical components of a vector?

A

Vh =Vcosθ

Vv =Vsinθ

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How is the mass of a galaxy estimated?

A

By measuring the orbital speed of stars within the galaxy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What (simply put) is time Dilation?

A

Moving clocks appear to run slow (to an outside observer).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the Time Dilation formula in terms of the Lorentz Factor?

A

t’ = t γ

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is meant by the terms elastic and inelastic collisions ?

A

In an elastic collision both momentum and energy are conserved. In an inelastic collision only momentum is conserved

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Write down the quantities and units for the equations
v = u + at
s = ut + 1/2at^2
v^2 =u^2 +2as

A 
s is displacement (m)
u is initial velocity (ms^-1) 
v is final velocity (ms^-1)
a is acceleration (ms^-2)
t is time (s)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

State Newton’s First, Second and Third Laws of Motion

A

NI – If the forces on an object are balanced the objects velocity remains constant.
NII – If there is an unbalanced force then the object accelerates.
NIII – For every action force there is an equal size but opposite direction force.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are three ways to find impulse?

A 
Average force x time 
or
Area under a force time graph
or
Change of momentum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe & explain the motion of a satellite.

A

Satellites are in free fall around a planet or star. They have a constant horizontal velocity and a constant vertical acceleration.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What do we mean by the phrase Conservation of Energy?

A

Energy is not created or destroyed it changes from one form to another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What do we get if we calculate the gradient or area of a velocity time graph?

A

Gradient calculates the acceleration. Area calculates the displacement.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is Proper Time, t ?

A

The time measured in a f.rame in which the clock is at rest relative to the event e.g. the clock actually on the spaceship. Time is always shorter in this frame.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What (simply put) is Length Contraction?

A

Moving objects appear shortened (to an outside observer.)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What do measurements of galaxy velocities and their distance from us tell us about the universe?

A

The universe is expanding

19
Q

How do you work out the component of weight acting down a slope?

A

Component of weight down slope

= mg sin θ

20
Q

Give a second example showing Time Dilation

A

Clocks on satellites e.g. GPS, run slow. Systems must take this into account if they wish to calculate an accurate position.

21
Q

What is Dilated Time, t’ ?

A

The time measured in a frame where you are observing the event from the outside e.g. on the planet watching the spaceship fly past. Time passes faster here. The moving clock seems to be running slow.

22
Q

What is Proper Length, l ?

A

The length measured in a frame in which the measurer is at rest relative to the event e.g. the length actually measured on the spaceship. Length is always longer in this frame.

23
Q

Formula for the Doppler Effect for sound

A 
f0 = fs(V/V(+or-)Vs) 
V = Speed of sound Vs = Speed of source f0 = Observed frequency fs = Source frequency
24
Q

Howdo you calculate a Z value? Give two methods

A

Z= Δ λ / λrest Z=v/c

25
Q

What is Dilated Length, l’ ?

A

The length measured in a frame where you are observing the event from the outside e.g. on the planet watching the spaceship fly past. The moving object length is shorter.

26
Q

Doppler Effect - if the source is approaching, do you add or subtract the source velocity in the divisor? Why?

A

Subtract the source velocity.

It makes the perceived frequency higher.

27
Q

State the second basic postulate of special relativity

A

The speed of light in a vacuum is the same for all observers

28
Q

What is Redshift?

A

A measure of the red- shift of an object, given as a fraction of the speed of light.

29
Q

What is Blueshift?

A

Waves coming from a source moving towards an observer are measured to have a higher frequency (bluer) than the source

30
Q

What is the Doppler Effect?

A

Observed change in frequency of a wave when the source is moving relative to the observer.

31
Q

Newton’s law of gravitation.

A

F=Gm1m2/r^2.

F	=	force
G	=	gravitational constant
m_1	=	mass of object 1
m_2	=	mass of object 2
r	=	distance between centers of the masses
32
Q

What is a Z value?

A

A measure of the red- shift of an object, given as a fraction of the speed of light.

33
Q

Formula for Hubble’s Law

A 
V = H0d         V = Recessional velocity of a galaxy Ho = Hubble’s constant
d = distance to the galaxy
34
Q

Which Greek Letter represents the Lorentz Factor?

A

Gamma

γ

35
Q

State the first basic postulate of Special Relativity.

A

Two observers moving at constant speed observe the SAME laws of Physics.

36
Q

Give evidence for the existence of dark matter

A

Stars in galaxies are orbitting faster than predicted.

37
Q

What is the Lorentz Factor?

A

1/√1-v ²/c ²

38
Q

State the formula for Length Contraction

A

l’=l√1-v²/c²

39
Q

State the formula for time dilation

A

t’= t /√1-vsquared/csquared

40
Q

Give evidence to support the Big Bang Theory

A

Cosmic Microwave Background Radiation.
The abundance of hydrogen and helium.
The darkness of the sky (Olber’s Paradox).
Large number of galaxies showing redshift.

41
Q

How is the age of the universe estimated from Hubble’s Law?

A

d/v = 1/Ho = age of universe

42
Q

Give one example showing time dilation

A

Moving clocks appear to run slow to an outside observer

43
Q

Describe the relationships between the temperature of a stellar object and the wavelength and irradiance of radiation emitted.

A

Peak wavelength is shorter for hotter objects. Hot objects emit more radiation per unit surface area per unit time.

44
Q

Give evidence for the existence of dark energy

A

Cosmic microwave background radiation
The abundance of hydrogen and helium
The darkness of the sky(Olbers paradox)
Large number of galaxies showing redshift

SMHS Higher Physics (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions