Physics 1 Markers Flashcards
Learn 1 markers
Units of joule?
N m (newton metres?
Units of watt?
J s^-1 (joules per second)
Units of newton?
Kg m s^-2 (kilogram meters per second squared)
Scalar vs vector
Scalar: only has magnitude
Vector: has magnitude and direction
List 5 scalar and 3 vector quantities
Scalar: density, energy, time, power, speed,
Vector: acceleration, weight, displacement
State Hooke’s law.
Extension is proportional to force (applies as long ad elastic limit is not exceeded)
Explain what plastic deformation is.
Material is permemantly deformed, even after stress/force is removed.
Define “ultimate tensile strength” of a material.
Maximum stress a material can withstand before fracture.
State what the gradient of a force extenion graph represents?
Force constant/spring constant,
K.
How do you find work done on a force extension graph?
Area under line.
Define the Young Modulus of a material and state when it applies.
Stress/Strain.
As long as elastic limit isnt exceeded/hookes law obeyed/linear region of stress against strain graph.
What form of energy is stored in metal wire when it is extended by a force?
Elastic potential or strain(energy)
What is the forcd constant of a spring?
Force per unit extension.
State 2 pairs of scalar quantities with the same units.
Pressure and stress
Moment and torque
Energy and work done
What is meant by terminal velocity?
Max velocity of a falling object when drag=weight.
Define velocity.
Rate of change of displacement.
Define work done by a force.
Work done= force x distance moved in direction of force.
Define density.
Mass per unit volume.
Define newton.
Net force when 1kg of mass hass acceleration of 1 ms^2.
Define braking distance.
Distance travelled from time brakes are applied to stop of car.
State factors which increase braking distance.
Greater mass
Worn brakes/faulty
Road surface
Gradient of road
State principle of moments.
“For equilibrium of an object, clockwise moments=anticlockwise moments about the same point”
Define moment of a force.
Moment= force × perpendicular distance from point or pivot.
Does mass of a particle change as it approaches speed of light?
Yes, it increases.
What technique does GPS use to locate position of cars?
Trilateration.
What is meant by centre of gravity of an object?
Point in which entire weight of object seems to act.
What is meant by a white dwarf
left over core of a Red Giant
Formula connecting arcsecs and parsecs
angle in arcsec= 1/distance in pc
What is meant by intensity
Power per unit area. I=P/A
Formula for calculating age of universe
t=1/Hubbles constant
What is big bang and name 2 pieces of evidence for it
Explosion which created the universe. Background radiation at 1 or 2 kelvin. Primordial elements.
Doppler Effect relations formula
v/c = ΔWL/WL = Δf/f
Cosmological Principle
Universe is homogeneous and isotropic
Define Homogeneous and Isotropic
Homogeneous:uniform density
Isotropic: Same in every direction
What is background radiation and how does it link to big bang
Intensity is same in all directions, about 2k, microwaves show that universe has cooled since big bang. “echo of the big bang”
3 properties of black holes
infinite density, light cant escape, singularity
