Answer:
C ) 1.53
Explanation:
The critical angle of a material is given by the formula

where
c is the critical angle
n is the refractive index
This formula is valid if the second medium is air (which is the case of the problem).
In this problem, we know the critical angle:

Therefore we can rearrange the equation to find the refractive index:

Answer:
2 m
Explanation:
The displacement of any body is the shortest distance in an object's path between its initial and final point.
The ball would travel 3 m from the point of throwing then fall down 5 m to the ground. The total distance traveled is 7 m.
The displacement of the ball will be the distance from the point of throwing to the ground i.e., 2 m as it is the shortest distance between the initial and final point of the ball's journey.
Answer:
It increases to three times it's original value.
Explanation:
B
Answer:
2Mg + O2 → 2MgO
Explanation:
this is what your looking for
Answer: B
Explanation:
Given that an object of mass 2 kg starts from rest and is allowed to slide down a frictionless incline so that its height changes by 20 m.
The parameters given from the question are:
Mass M = 2kg
Height h = 20m
Let g = 9.8m/s^2
At the bottom of the incline plane, the object will experience maximum kinetic energy.
From conservative of energy, maximum K.K.E = maximum P.E
Maximum P.E = mgh
Maximum P.E = 2 × 9.8 × 20 = 392 J
But
K.E = 1/2mv^2
Substitute the values of energy and mass into the formula
392 = 1/2 × 2 × V^2
V^2 = 392
V = sqrt( 392 )
V = 19.8 m/s
V = 20 m/s approximately