A) Kilograms per cubic meter. Every other option either contains pounds or feet, which are both units of measurement from the standard system, not the metric system.
Acceleration formulae is:
a=Fnet/mass
According to the question
a=7500N/1500kg
a=5m/s sq.
Let both the balls have the same mass equals to m.
Let
and
be the speed of the ball1 and the ball2 respectively, such that

Assuming that both the balls are at the same level with respect to the ground, so let h be the height from the ground.
The total energy of ball1= Kinetic energy of ball1 + Potential energy of ball1. The Kinetic energy of any object moving with speed,
, is 
and the potential energy is due to the change in height is
[where
is the acceleration due to gravity]
So, the total energy of ball1,

and the total energy of ball1,
.
Here, the potential energy for both the balls are the same, but the kinetic energy of the ball1 is higher the ball2 as the ball1 have the higher speed, refer equation (i)
So, 
Now, from equations (ii) and (iii)
The total energy of ball1 hi higher than the total energy of ball2.
The circuit was installed in UF cable which requires a minimum burial depth of 6 inches for this circuit.
<h3>
UF cable</h3>
UF cable is used as an underground feeder cable to distribute power from an existing building to outdoor equipment. UF cable can also be used as direct burial cable.
For the 24-volt branch circuit installed, the minimum burial depth will be 6 inches.
Thus, the circuit was installed in UF cable which requires a minimum burial depth of 6 inches for this circuit.
Learn more about UF cable here: brainly.com/question/8591560