paper 1

Question 1

State the
principle of moments

Answer 1

he sum of the clockwise moments
(about the same point) = sum of anticlockwise moments

Question 2

explain the term
centripetal force

Answer 2

orce acts perpendicularly to the direction of motion

Question 3

state
Hubble’s law

Answer 3

Recessional speed / velocity of
galaxy
is proportional to its
distance (from us)

Question 4

Suggest why measurements for our nearest galaxies can deviate from the current
Hubble’s law trend line

Answer 4

gravitational attraction between nearby galaxies affects
motion
/ clustering of galaxies

Question 5

Suggest why measurements for galaxies at the largest distances deviate from the
Hubble’s law trend line

Answer 5

Expansion rate may not have been constant / non-linear
expansion /effect of dark energy causing accelerating rate of
expansion

Question 6

A student wishes to test the equation F =mv^2 / r or a constant force F
using a whirling bung in the laboratory.
Describe with the aid of a labelled diagram how an experiment can be conducted, and how the data can be analysed to test the validity of this equation for a constant force

Answer 6

stopwatch used to measure time period
suitable scale to measure radius
whirl bung with constant frequency
measure time for several time periods
vary frequency and radius
plot graph

Question 7

Describe the energy changes that will take place as the mass moves from the lowest point in
its motion through the equilibrium position to the highest point in its motion.T

Answer 7

EPE decreases (from bottom to top)
GPE increases

KE starts at zero, finishes at zero and
max at equilibrium point.

Total energy
(of mass and
spring)
decreases over time

Question 8

State what is meant by the
internal energy
of the substance

Answer 8

The sum of the (random) kinetic and
potential energy of atoms or molecules in a substance