Calculating Impulse for a Truck Slowing Down: Momentum and Vector Help

[butz3]

i know that the formula for impulse is f(delta)t. my question ask " a truck with a mass of 1.20 x 10^3 kg has its brakes applied for 5.50s as it slows down from 24.0m/s, west to 10.4m/s west. determine the magnitude and direction of the impulse provided by the brakes." i know you need to use the formula
f(delta)t = m(delta)(vf-vi). but since i want the impulse do i just fill in the right side of the formula and git impulse or do i use the time also. thanks.

 

[Fookie]

u can safely ignore "time=5.50s" as impulse is independant of time.


just impulse= (1.20 x 10^3)(24.0-10.4)

 

[robphy]

The impulse is the left-hand-side: (F_avg)(Delta t).
By the impulse-momentum theorem, it then follows that it is equal to the change-in-momentum.