<u><em>Explanation:</em></u>
This exposes the individual to danger. <em>Remember</em>, the Newton Law of motion which says that an object under the state of rest will remain in that state (inertia) unless when acted upon by an external force.
In this scenario, standing at the back of the pickup truck presents danger especially if the truck suddenly stops; this individual would experience an upward thrust due to inertia that may disbalance him.
if the velocity of the car reduces from 70km/h to 50km/h then the speed of the car will be equal to the speed of the lorry...
thus the relative velocity will be 0
Answer:
Let the second medium be air (n₁=1)
The refractive index n₂ of the medium where first medium is air is found (a)
(a) n₂ = 2
Explanation:
Critical angle can be defined as the angle of incidence that provides the angle of refraction of 90°.
Refractive index of a medium can be defined as a number that describes that how fast a light will travel through that medium.
Critical angle and Refractive index are related by:


To find refractive index of medium with respect to air, substitute n₁=1 (Refractive index of air is 1)
Also θ(critical)=30°
Find n₂ :

Answer:
Option 5.
Explanation:
Many of the properties of water like high specific heat, cohesion, high vaporization heat, etc can be contributed to the polar nature of water molecule.
Water being a polar molecule as it contains positively charged hydrogen and an electro-negative oxygen which results in uneven or non uniformity in sharing of electrons which leads to dipole formation and hence polarization of the molecule due to which it attracts its neighboring molecules.
This polar nature imparts the properties like cohesion, surface tension , adhesion, etc due to the presence of hydrogen bonds in water molecule.