The smallest particle of an element that still retains the chemical properties of it is an atom.
The answer is C : 15.7 m/s
Use the idea of : momentum before collision = momentum after collision
Before collision;
For car:mass=1.1×10^3, velocity=22
For truck:mass=2.3×10^3, velocity=0
After collision;
For car:mass=2.3×10^3, velocity=-11
For truck:mass=2.3×10^3, velocity=V
(1.1×10^3 × 22) + (2.3×10^3 × 0) = (1.1×10^3 × -11) + (2.3×10^3 × V)
24200 = -12100 + 2.3×10^3V
2.3×10^3V = 36300
V = 15.7 m/s
Given :
Number of moles , n = 36.25 mol .
Molarity , M = 1.25 M .
To Find :
The volume of water required .
Solution :
Moarity is given by :
So , 
Here , n is number of moles and M is molarity .
Putting all values in above equation , we get :
Therefore , volume of water required is 29 L .
