<span>In a
real machine, the work output is always less than the work input is true. The answer
is letter A. it follows the law of entropy where no energy can be converted completely
into work. Under this law, Carnot’s theorem states that Carnot’s engine can
perform 100% of work. However, no such engine has ever succeeded the conversion
of work into 100%. The greatest efficiency so far is at 80%. Because there will always be factors that
could affect the conversion of work. </span>
Gravity is all ways pulling down and the normal force acting on top of the object and for it to have to push or pull to the object
Net force on the car=F=4.8 x 10³ N
Explanation:
mass of car= 1.2 x 10³ Kg
initial velocity= Vi=0
Final velocity= Vf= 20 m/s
time = t= 5 s
Using kinematic equation,
Vf= Vi + at
20= 0 + a (5)
5 a=20
a= 20/5
a= 4 m/s²
Now force is given by F = ma
F= 1.2 x 10³ (4)
F=4.8 x 10³ N
Well, electrons can be converted into a atomic number so if SE atomic number is 34 that means it has 34 electrons. AI has a atomic number of 13 meaning it has 13 electrons.
So the difference is that SE has more electrons then AI.
Hope this helped. :D