Answer:
4.5kg m^2 s−1
Step-by-step explanation:
Step one:
the expression for angular momentum is given as

m = mass = 0.5kg
v = velocity = 7.5m/s
r = radius= 1.2m
Required
L = angular momentum
Step two:
substitute into the expression
L=0.5*7.5*1.2
L=4.5kg m^2 s−1