Final answer:
The impulse of the force over the given time interval is 90 Ns.
Step-by-step explanation:
To find the impulse of the force, we need to calculate the integral of the force function over the given time interval. The formula for impulse is:
Impulse = ∫(F dt)
Plugging in the values for a and b, we get:
F = 15t - 20t^2
Integrating this equation from 0 s to 3.0 s:
Impulse = ∫(15t - 20t^2) dt
Evaluating the integral gives us an impulse of 90 Ns.