Take into account that the weight of a person can be calculated by using the following formula:
W = m·g
where m is the mass and g the gravitational acceleration constant g = 9.8m/s².
In this case, W = 343 N. Then, solve the previous equation for m and replace the values of W and g, as follow:
m = W/g
m = (343 N)/(9.8 m/s²)
m = 35 N·s²/m
m = 35 kg·m·s²/s²
m = 35 kg
Hence, the mass od the person is 35 kg
