Choose all the answers that apply.

which of the following equations are balanced?

a) 2h2 + o2 → 2h2o
b) 2s + 3o2 → 2so3
c) li + cl2 → licl
d) 2k + 2h2o → h2 + 2koh
e) 2fe + cu(no3)2 → 2cu + fe(no3)2

#a.2H2 + O2 → 2H2O

#b. 2S + 3O2 → 2SO3

#d. 2K + 2H2O → H2 + 2KOH

In this case;

This is because the number of atoms of each element is not equal on both side of the equation/

(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