Initial velocity (u) = 90km/hr = 90/3.6 m/s = 25m/s
final velocity (v) = 18km/hr = 18/3.6 m/s = 5m/s
acceleration = (v-u)/t = (5-25)/4 = -5 m/s2
change in momentum = m(v-u) = 1200(5-25) = -24000 kg•m/s
F = ma = 1200 x -5 = -6000 N
I really wish I could help but I really dk the answer and I need points asappppp so that I can get answers to my questions so I can give them in rnnnn!!! Sorryyyyy (atleast I'm being honest)
Explanation:
using Ohm's law which is defined as V=IR
where V is the voltage, I is the current and R the resistance