Test 9 completed Flashcards
Unit for spring constant?
N/cm
How to make the resultant force greater for an object traveling in circles? {3 points}
- Bigger mass
- Bigger speed
- Smaller radius
A ball hits an object. Calculate the velocity of the object.
momentum=momentum
ball p = ball p + object p
ball bounces backwards, so velocity is negative
The wavelength is smaller than the gap.
less curved
The current–voltage graph of a filament lamp , explain its shape.
As the temperature increases, resistance increases, so more voltage is required for the same increase in current.
State what is at point X to produce the field pattern shown in Fig. 7.1.
positive point charge
With friction, electrons are..
lost
Explain how the structure of an electrical conductor differs from the structure of an electrical
insulator.
Conductors have free electrons
How does one wavelength look like?
Two halves on the top
A graph to represent a.c as a coil turns. What does one turn look like? What do the peaks and troughs look like? The position at 0?
One turn is one wavelength.
The peaks are horizontal.
At 0, they are vertical.
Household smoke alarm:
type of radioactive emission-
explanation-
half-life-
alpha, highly ionising, 100 years
measuring the thickness of aluminium strips produced in a factory
type of radioactive emission-
explanation-
half-life-
beta
absorption depends on thickness of aluminium
any number of years
State two different sources of background radiation.
- radon gas (in the air)
- rocks OR buildings
- food OR drink
- cosmic rays
Hubble’s law equation and what is it
Hubble’s constant: H0=d/v
Hubble’s law:
v=H0d
Distant galaxies are moving away from Earth with a speed, v, proportional to their distance, d from Earth
Numerical value of Hubble’s constant?
2.2 x 10^-18
Work out age of universe.
t
Universe= hubble’s constant inverse= 1/ constant= 4.5x10^17 s= 14.4 x 10^9 years
State when cosmic microwave background radiation (CMBR) was formed and where we
detect it coming from.
shortly after the Universe was formed
OR shortly after the Big Bang
all points in space
Calculate the change in total kinetic energy of the ball and object during the collision.
energy before and after
k.e of ball and object both times
INCLUDE EVERYTHING MWAHAHAH
In that killy circuit, what should I remember when calculating voltage? What else?
Resultant.
Where the current is not flowing, current will be zero.
Draw an arrow to indicate the direction of the force on a negative point charge placed at the positive point charge.
arrow towards positive point charge
