A2000-kilogram car uses a breaking force of 12000 newton’s to stop in 5 seconds. what impulse acts on the car?

i honestly don't even know but yahoo answers says :

Impulse causes momentum to change, which means:  

Impulse = change in momentum, or in equation form:  

F∆t = (mv)2 – (mv)1  

so p (impulse)= mass times velocity so the mass is 2,000kg and the velocity is 12,000N/5s.  

speed is basically velocity so you have to calculate how many newtons per one second, so 12,000/5s-- just divide the numerator and denominator by 5. Also, velocity and speed are measured in N/s.

resonant frequency