Dynamics And Space Flashcards
Scalars? (5)
Distance Speed Energy Mass Time
Equation for displacement?
Displacement= velocity x time
The gradient of a velocity time graph?
The gradient of a velocity time graph gives the acceleration.
Perpendicular, along?
Mgcos(angle)
Down, parallel?
Mgsin(angle)
Momentum equation?
P=mv
Units of momentum?
Kgms-1
What is an inelastic collision?
When only momentum is conserved.
What is an elastic collision?
When kinetic energy AND momentum are conserved.
What type of collision are explosions?
Explosions are inelastic because only momentum is conserved.
Impulse equation?
Ft=mv-mu
Does impulse last for a long time?
No impulse lasts for a short time.
What can the impulse equation show?
The impulse equation shows the change in momentum.
What is a projectile?
An object with a forward motion through the air but also a downward motion due to gravity, resulting in a curved path.
Equation for vertical velocity?
V=u+at
Explain geostationary satellites:
They must be above the earth 35000 km to be in free fall and have an orbital period of 24 hours.
How to determine gravitational field strength?
The larger the mass the larger the gravitational field strength.
The effect of the moon on the earth?
The moon influences the tides on Earth because when two masses become in close proximity to each other a force of attraction is between them.
Maxwells statement on light?
Speed of light in a vacuum has a fixed value.
Einsteins observations (2)
The speed of light is constant in all frames of reference.
Galilean invariance is true in all frames of reference.
What is Doppler effect?
The change in frequency observed when a source of sound waves is moving relative to an observer.
Explain red shift:
When light from objects are moving away from us, it is shifted to the red end of the spectrum and have longer wavelengths.
Red shift calculation for stars?
If the star is moving away the number will be positive, if it’s moving towards us it will be negative.
What is Hubbles Law?
Hubbles Law is the relationship between the recession velocity of a galaxy and its distance from us.
What has the law proved? (2)
That galaxies are moving away from us and the galaxies further away from us are moving faster.
Percentage of dark matter in the universe?
25% of the universe is made up of dark matter and 5% of the universe is made up of normal matter.
What has given us evidence of dark matter?
The masses and velocities of galaxies have given evidence of dark matter.
What percentage of the universe is dark energy?
70% of the universe is made up of dark energy.
What is dark energy causing?
Dark energy is believed to be able to overcome gravitational attractions and is causing the universe to have an accelerating expansion rate.
How were temperature measurements gained? (2)
Temperature measurements were gained using cosmic background radiation. A satellite called the cosmic background explorer provided evidence of the temperature of the earth.
What did the cosmic background explorer support evidence of?
The cosmic background explorer supports evidence of the Big Bang theory as it records information of the expansion and cooling of the universe following the Big Bang.
Other evidence of the Big Bang? (2)
Even distribution of matter in the universe.
An abundance of light elements such as Helium throughout the universe.
Big Bang theory version: (3)
The Big Bang suggests the Universe began as a singularity then space expanded very quickly. This started the formation of atoms that soon led to form stars and galaxies. The universe is cooling while also expanding but in the beginning it was very small and hot.
Range?
V=d/t and use the horizontal speed
Explain the effect of increasing the angle of projection on the kinetic energy of the shot at release?
The kinetic energy is less because as the angle increases the speed decreases.
