The driver of a compact car suddenly applies the brakes hard for 2 seconds. As a result, an average force of 5000 N is exerted on the car to slow it.
What is the change in momentum, that is the magnitude and direction of the impulse, on the car?
Thanks for your help!Will someone please help me with physics? I don't know how to find momentum?Momentum is mass*velocity.
Impulse is force*time and causes a CHANGE of momentum.
In this case impulse is 5000*2 = 10,000 N s, the same as 10,000 kg m/s (momentum units)
This is opposite the direction of the car's motion.
(Dimensional analysis: by Newton's law f=ma, or m=f/a, which says that the units of mass(kg)= units of force(N)/(units of m/s^2 or kg = N/(m/s^2) or kg = N s^2/m so momentum units kg m/s = N s the units of impulse)Will someone please help me with physics? I don't know how to find momentum?force is proportional to rate of change of momentum,
i.e
F = 螖(mv)/t
rearranging the equation gives:
Ft = 螖(mv)
so impulse and change of momentum are same.
5000*2 = 10,000 Ns or Kgm/s
direction is in opposite direction to forward motion
either units apply but if question asks for impulse it's usually given in Ns, and Kgm/s for momentum
