Answer:
Explanation:
The work done
and the energy taken
by a heat engine are related to the efficiency
by the expression

The efficiency is
=25%, the numerical form of this percentage is 0.25 and the energy taken is
=200J. Replacing in the formula:

Explanation:
Given: Initial Velocity=0
Final Velocity= 20 m/s
Time= 4 s
Accleration: Unknowns
Use kinematic equation




so a = 5 m/s^2
Answer:
The value is 
Explanation:
From the question we are told that
The length of the wire is 
The current density is 
The conductivity is
Generally conductivity is mathematically represented as

Here R is the resistance which is mathematically represented as

Here I is the current which is mathematically represented as

So

And

=> 
=> 
=> 
=> 
Answer: Option (a) is the correct answer.
Explanation:
Resources which are created by human beings are known as man-made resources.
For example, glass, rayon, nylon etc are all man-made resources.
Whereas resources which are naturally created are known as natural resources.
For example, wind, air, water etc are all natural resources.
Thus, we can conclude that out of the given options time is not a natural resource.