Answer:
Mass and velocity.
Explanation:
Kinetic energy <u>is the energy that an object has due to its movement</u>, mathematically it is represented as follows:
where 
is the mass of the object, and 
is its velocity at a given point in time.
So we can see that to find the kinetic energy just before the ball hits the gound, we need the quantities:
- mass of the ball
- velocity of the ball before it hits the ground
With the knowledge of these two quantities the kinetic energy of the ball before touching the gound can be determined.
Answer:
The answer is 10.857mJ
Explanation:
The energy stored in this solenoid is given by the below mentioned equation,
where L the inductance of this solenoid is given by the below mentioned equation,
Plugging this into the energy equation you obtain the equation for the total energy stored in the magnetic field of the solenoid, given by,
where 
is the permeability of free space which equals to 
. Plugging all the quantities into the above equation from the data in the question after converting to standard units. of meters instead of centimeters, we get for the energy stored in the coil,
I’m pretty sure it is an object with a net force of zero. All forces are balanced and EQUAL
