Metals tend to readily lose electrons and form cations. Most of them react with atmospheric oxygen to form metal oxides. However, different metals have different reactivities towards oxygen (unreactive metals such as gold and platinum do not readily form oxides when exposed to air
To solve this problem it is necessary to apply the concepts of heat change and thermal efficiency.
The heat rate can be expressed under the function
Where,
m = Mass
Enthalpy at each state
Our values are given as,
From the tables of Enthalpy of Water at 200°C (Saturated liquid state)
At the same time for 80°C
Applying the equation of Heat,
Replacing,
Therefore the efficiency would be
Therefore the actual thermal efficiency of the turbine in percent is 0.0579.
Here when an object is placed on the level floor then in that case there are two forces on the object
1). Weight of object downwards (mg)
2). Normal force due to floor which will counterbalance the weight (N)
so when no force is applied on the box at that time normal force is counter balanced by weight.
Now here it is given that A person tried to lift the box upwards
So now there are two forces on the box
1). Applied force of person
2). Normal force due to ground
So now these two forces will counter balance the weight of the crate
So we can write an equation for force balance like
given that
here
m = 30 kg and
g = acceleration due to gravity = 10 m/s^2
now from above equation
So force applied by the person must be 150 N
B. is it i just got done this in class like two weeks ago hope it helps