A 1391.3 kg car is traveling at 29.8 m/s when the driver takes his foot off the gas pedal. It takes 4.9 s for the car to slow down to 20 m/s. How large is the net force slowing the car

Fnet = 2782.6 N

Explanation:

Newton's 2nd Law states that the net force applied to an object, is equal to its mass times the acceleration.By definition, acceleration is the rate of change of velocity with respect to time, as follows:

       

        where Δv = vf - v₀ and Δt = tfi - t₀, replacing by the givens:

       

       Δt = 4.9 s

       ⇒

We can now apply Newton's 2nd Law, solving for Fnet, as follows:

       

The magnitude of the is net force (How large it is ) is just:Fnet = 2782.6 N