Please what is the formula for finding mole and give a worked example

see explanation

Explanation:

number of moles = mass ÷ relative formula mass

e.g.

Calculate the number of moles of carbon dioxide molecules in 22 g of CO2.

Ar (relative atomic mass) of C = 12, Ar of O = 16

Mr (relative formula mass) of carbon dioxide = 12 + 16 + 16 = 44

number of moles = 22 ÷ 44 = 0.5 mol

ljjjljlj kjlk,ljym jlyu; jm; l mumytj

(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