May 2024 Exam Questions and
Answers
Gravitational Field - Answer>> A region in which an object that
has mass experiences a force
Field Lines - Answer>> Arrows which indicate the direction and
relative strength of a field. Arrows show the way in which a rest
mass would experience the force of attraction.
Equipotentials - Answer>> Lines drawn to indicate points of
equal potential. Cross field lines at 90 degrees
Newton's Law of Gravitation - Answer>> Every particle in the
universe attracts every other particle with a force that is directly
proportional to the product of their masses and inversely
proportional to the square of the distance between their centre's
F ~~ Mm/r^2
Gravitational field strength - Answer>> The force acting on a
body per unit mass
Gravitational Potential Energy - Answer>> Potential energy is
the work done in moving an object with mass from Infinity to that
point in the field
E=-gMm/r for radial field E=mg•dh (Scalar)
Absolute Gravitational potential - Answer>> The absolute
gravitational potential at a point is the work done per unit mass in
moving a body from Infinity to that point in the gravitational field
V=-Gm/r (scalar)
, Orbital time period - Answer>> GMT^2 =4pi^2 •r^3 therefore
T^2 prop R^3
orbital velocity - Answer>> (GM/r)^1/2
escape velocity - Answer>> (2GM/r)^1/2
Satellites in geosynchronous orbit - Answer>> T=24hrs
Orbital Radius roughly 36,000km
Remember the subtle difference between geosynchronous and
geostationary, Which stay above the same point on Earth.
Satellites in a non-geosynchronous/polar orbit - Answer>>
Different, usually smaller T than earth.
Activity - Answer>> Number of emissions per second measured
in Bq
Alternating Current (AC) - Answer>> A flow of electric charge
that continuously changes its direction and magnitude
Avogadro's Law - Answer>> equal volumes of gases at the
same temperature and pressure contain equal numbers of
molecules
Boltzmann's constant - Answer>> a physical constant relating
the average kinetic energy of particles in a gas with the
temperature of the gas; it is the gas constant R divided by
Avogadro's number (1.38x10^-23 J K^-1)
Boyle's Law - Answer>> P1V1=P2V2