Answer:
Rectangular path
Solution:
As per the question:
Length, a = 4 km
Height, h = 2 km
In order to minimize the cost let us denote the side of the square bottom be 'a'
Thus the area of the bottom of the square, A = 
Let the height of the bin be 'h'
Therefore the total area, 
The cost is:
C = 2sh
Volume of the box, V =
(1)
Total cost,
(2)
From eqn (1):

Using the above value in eqn (1):


Differentiating the above eqn w.r.t 'a':

For the required solution equating the above eqn to zero:


a = 4
Also

The path in order to minimize the cost must be a rectangle.
Answer: The chemical energy is converted to heat, light ,sound and kinematic movements.
Explanation:
An exploding firework is essentially a number of chemical reactions happening simultaneously or in rapid sequence. When you add some heat, you provide enough activation energy (the energy that kick-starts a chemical reaction) to make solid chemical compounds packed inside the firework combust (burn) with oxygen in the air and convert themselves into other chemicals, releasing smoke and exhaust gases such as carbon dioxide, carbon monoxide, and nitrogen in the process. For example, this is an example of one of the chemical reactions that might happen when the main gunpowder charge burn.
some of the chemical energylocked inside them is converted into four other kinds of energy (heat, light, sound, and the kinetic energy of movement). According to a basic law of physics called the conservation of energy.
Answer:
Particle-antiparticle annihilation is the result of a direct interaction between a particle and its corresponding anti particle, like a proton and an anti-proton or an electron and a positron. The result of such interaction is the production of two powerful gamma rays, each of whom has an energy roughly equal to E = mc^2, where m is the mass of the particle.
Answer:
a. you speak clearly and well
Explanation: