Avariety of factors can affect the angle of repose, including:
a) larger, more angular particles form steeper slopes than smaller, rounder particles.
b) higher coefficients of friction result in steeper slopes.
c) in dry conditions, friction holds closely packed particles in place.
d) when small amounts of water are present, surface tension between the water and the particles increases cohesion and allows for steeper slopes.
e) however, large amounts of water reduce friction and allow particles to move downslope.
which factor might explain the variation in the angles you explored in the previous parts of the assignment?