Answer:
Net force, F = 44.66 N
Step-by-step explanation:
It is given by,
Initial velocity of the person, u = 0
Final velocity of the person, v = 0.68 m/s
Distance, s = 0.428 m
Combined mass of the person and the kayak, m = 82.7 kg
We need to find the net force acting on the kayak i.e.
F = ma...........(1)
Firstly, we will calculate the value of "a" from third equation of motion as :
![v^2-u^2=2as](https://img.qammunity.org/2020/formulas/physics/middle-school/kzr98dbu2wfj2ipzjwf8lasb185fsfra2y.png)
![a=(v^2-u^2)/(2s)](https://img.qammunity.org/2020/formulas/physics/college/nnih5mejyth9cl990unq25l2z7yus5r04b.png)
![a=((0.68\ m/s)^2-0)/(2* 0.428\ m)](https://img.qammunity.org/2020/formulas/physics/college/kv7ej5dvigitmet3coq53foioh9omlcc6d.png)
![a=0.54\ m/s^2](https://img.qammunity.org/2020/formulas/physics/college/txfrcj2jvpgeas084g0r8c79z3okdlr9vn.png)
Put the value of a in equation (1) as :
![F=82.7\ kg* 0.54\ m/s^2](https://img.qammunity.org/2020/formulas/physics/college/jryhkr99mswrrywwh8lyjlp0db4a63l9fk.png)
F = 44.66 N
So, the net force acting on the kayak is 44.66 N. Hence, this is the required solution.