Answer:

Explanation:
The expression for the second law of motion is given below:
h = 
<u>For first half distance</u>
Object is initially at rest, so its initial speed u = 0
Object falls at half the distance, so h = h/2 where t = t1
Hence, we have

<u>For second half distance:
</u>
Similarly,
where t = t1 + t2 and u= 0
Using equation 2 by equation 1
we obtain 
Hence 
Hence 
Answer:
Chemical energy to thermal(heat) energy
Explanation:
A gas burner contains chemical hydrocarbon such as methane, this methane is highly flammable.
The gas burner which contains methane when lighted up converts the chemical energy in the chemical to heat energy through the fire it produces. The fire then helps in heating up the surface it is applied to.
<h2>Answer:</h2>
The refractive index is 1.66
<h2>Explanation:</h2>
The speed of light in a transparent medium is 0.6 times that of its speed in vacuum
.
Refractive index of medium = speed of light in vacuum / speed of light in medium
So
RI = 1/0.6 = 5/3 or 1.66
Answer:
The box is moved at constant speed, then the change in kinetic energy is zero.
Explanation:
Let suppose that box moves at constant speed, meaning that its kinetic energy (
), measured in joules, is expressed by the following equation:
(1)
Where:
- Mass, measured in kilograms.
- Speed, measured in meters per second.
If the box moves at constant speed, then we notice that
, therefore,
. In a nutshell, if the box is moved at constant speed, then the change in kinetic energy is zero.
Acceleration = -12 / 8 = - .... m/s^2