The average force exerted on the dolphin can be calculated using the formula:
F = m x a
where F is the force, m is the mass of the dolphin, and a is the acceleration.
The acceleration of the dolphin can be calculated using the formula:
a = (v_f - v_i) / t
where v_f is the final velocity, v_i is the initial velocity, and t is the time taken.
Substituting the given values, we get:
a = (7.50 m/s - 12.0 m/s) / 2.30 s = -1.96 m/s^2
The negative sign indicates that the acceleration is in the opposite direction to the motion of the dolphin.
Substituting the mass of the dolphin and the acceleration into the formula for force, we get:
F = 35.0 kg x (-1.96 m/s^2) = -68.6 N
The negative sign indicates that the force is in the opposite direction to the motion of the dolphin.
Therefore, the average force exerted on the dolphin to slow it down was 68.6 N.