[tex]\\ \rm\bull\longmapsto F=ma[/tex]
[tex]\\ \rm\bull\longmapsto m=\dfrac{F}{a}[/tex]
[tex]\\ \rm\bull\longmapsto m=\dfrac{721}{10}[/tex]
[tex]\\ \rm\bull\longmapsto m=72.1kg[/tex]
As per the formula of weight, Arnold's mass is 73.5 kg.
The weight of an object is the product of it's mass and the acceleration due to gravity.
Given, Arnold's weight is 721 N.
The acceleration due to gravity is 9.81 m/s²
We know, weight = mass × acceleration due to gravity
⇒ Mass = weight/ acceleration due to gravity
⇒ Mass = 721/9.81
⇒ Mass = 73.5
Learn more about the weight of an object here: https://brainly.com/question/23312072
#SPJ3