Answer:
[tex]102\; {\rm N}[/tex].
Explanation:
When an object of fixed mass [tex]m[/tex] accelerates at a rate of [tex]a[/tex], the resultant force (the net force) on the object would be the product of mass and acceleration:
[tex](\text{resultant force}) = (\text{mass})\, (\text{acceleration})[/tex].
The question implies that the water skier is accelerating at the same rate as the boat: [tex]1.5\; {\rm m\cdot s^{-2}}[/tex]. Hence, the resultant force on the [tex]68\; {\rm kg}[/tex] water skier would be:
[tex]\begin{aligned}(\text{resultant force}) &= (\text{mass})\, (\text{acceleration})\\ &= (68\; {\rm kg})\, (1.5\; {\rm m\cdot s^{-2}}) \\ &= 102\; {\rm N}\end{aligned}[/tex].
