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:
Therefore, the moment of inertia is:
Explanation:
The period of an oscillation equation of a solid pendulum is given by:
(1)
Where:
- I is the moment of inertia
- M is the mass of the pendulum
- d is the distance from the center of mass to the pivot
- g is the gravity
Let's solve the equation (1) for I
Before find I, we need to remember that
Now, the moment of inertia will be:
Therefore, the moment of inertia is:
I hope it helps you!
<h2>Answer:</h2>
<u>Ball A has more kinetic energy</u>
<h2>Explanation:</h2>
As we know that Kinetic energy is given by
K. E = 1/2 mv²
Since K E is dependent upon both mass and velocity so increasing mass will produce more kinetic energy if the speed remains constant
As the mass of ball A is greater than ball B so we can say that the kinetic energy of ball is more than ball B
