ur answer is A or also known as
When you push a child on a swing, you are doing work on the child because you are pushing against the force of gravity
hope this helps :)
Answer:
He could re read his answear.
Explanation:
Answers:
a) 5400000 J
b) 45.92 m
Explanation:
a) The kinetic energy 
of an object is given by:
Where:
is the mass of the train
is the speed of the train
Solving the equation:
This is the train's kinetic energy at its top speed
b) Now, according to the Conservation of Energy Law, the total initial energy is equal to the total final energy:
Where:
is the train's initial kinetic energy
is the train's initial potential energy
is the train's final kinetic energy
is the train's final potential energy, where 
is the acceleration due gravity and 
is the height.
Rewriting the equation with the given values:
Finding :
Answer:
The Nucleus
Explanation:
The nucleus contains the majority of an atom's mass because protons and neutrons are much heavier than electrons, whereas electrons occupy almost all of an atom's volume. I hope this helps you :D
Answer:
The frictional force between two bodies depends mainly on three factors: (I) the adhesion between body surfaces (ii) roughness of the surface (iii) deformation of bodies
