Final answer:
To find the net force exerted by the water on the swimmer, calculate the change in momentum of the swimmer using the equations for impulse and initial velocity. The net force exerted by the water is 1225 N.
Step-by-step explanation:
To find the net force exerted by the water on the swimmer, we need to calculate the change in momentum of the swimmer.
Using the equation for impulse:
F * t = m * (v_f - v_i)
Where F is the force, t is the time, m is the mass, v_f is the final velocity, and v_i is the initial velocity.
Since the swimmer comes to a stop 2.0 m below the surface, the final velocity is 0. The initial velocity can be calculated using the equation:
v_i^2 = v_f^2 + 2 * a * d
Where v_i is the initial velocity, v_f is the final velocity, a is the acceleration, and d is the displacement.
Plugging in the values, we can solve for v_i and then use it in the first equation to find the net force exerted by the water.
After calculating, we get a net force of 1225 N.