Explanation:
string roller is called an example of wheel and axel because The thin rod which needs to be turned is called the axle and the wider object fixed to the axle, on which we apply force is called the wheel.
hence the we apply force on the roller and the string gets tight.
There are four laws of thermodynamics.
Zeroeth Law of Thermodynamics: Two systems in thermal equilibrium with a third system are in thermal equilibrium to each other.
First Law of Thermodynamics: The change in a system's internal energy is equal to the difference between heat added to the system from its surroundings and work done by the system on its surroundings.
Second Law of Thermodynamics: It is impossible for a process to have as its sole result the transfer of heat from a cooler body to a hotter one.
Third Law of Thermodynamics: The entropy of a perfect crystal at absolute zero is exactly equal to zero.
In 1842, Julius Robert Mayer discovered The law of conservation of Energy. It its most compact form, it it now called The first law of Thermodynamics
Energy can neither be created nor destroyed, it can only be changed to another form of energy.
Answer:
a
Explanation:
because they are easily reduced and oxidised
Answer:
Explanation:36.05 km
Given
First car travels 
South
then turns and travels 
east
Suppose south as negative y axis and east as positive x axis
So, 
Displacement is the shortest between initial and final point
Dispalcement
Displacement
Displacement
Magnitude 
Magnitude
