Calculate the impulse imparted when a 3,000-kg car hits a wall at 60. m/s and comes to a stop.

I know its 1.8*10^5, but what I don't know is if it would be positive or negative. I'm assuming positive ? But I'm not really sure.

Question

Calculate the impulse imparted when a 3,000-kg car hits a wall at 60. m/s and comes to a stop.

I know its 1.8*10^5, but what I don't know is if it would be positive or negative. I'm assuming positive ? But I'm not really sure.

anonymous · Answer

If impulse is change in momentum, we can write it like this$$J = m(V_f - V_i)$$Isn't our final velocity less than our initial? What "sign" does that give you impulse?

anonymous · Answer

Sorry, my computer froze. & since it's less, it would be negative ?

anonymous · Answer

Correct.