Specific heat of water (cal) = 1 cal/gC
How many joules of heat are given off when 10 g of water cool from 100C 1 point
to 25 C? In this question, which specific heat of water should you use in
your calculation?
4.18 J/gC
O 1 cal/gC
How many joules of heat are given off when 10 g of water cool from 100C 1 point
to 25 C? (Use 1 sig fig and label units)

(newtons first law)

conservation of momentum law states :

momentum before collision = momentum after collision

momentum p (kg-m/s)= mass * velocity

say moving car=1 000 kg, velocity = 10 m/s then p = 1 000*10= 10 000 kg-m/s

say still car = 2 000 kg, velocity = 0 m/s then p = 2 000* 0 = 0 kg-m/s

total momentum prior to collision = 10 000 + 0 = 10 000 kg-m/s

momentum after collision = 10 000 kg-m/s

mass now = 1 000 kg+2 000 kg = 3 000 kg

10 000 = 3 000 kg* velocity m/s

10 000/3 000 = velocity

3.33 m/s = velocity after collision

an impulse is a force applied over time , momentum is exclusive of external forces and a perfect collision is implied

4d^55s^1 ( third choice)