The center of mass is given with this formula:

Velocity is:

So, for the velocity of the center of mass we have:

In our case it is:
What is the question asking?
Answer:
Electrical
Explanation:
She uses a battery, which is electrical.
It doesn't operate using chemicals, heat, or light
Explanation:
What exactly are u looking for?
Answer:
A. To find the mass flow rate.
We use= 220 x 0.355/ 60
= 1.3kg/s
B. Volume flowrate is = mass flowrate / density
But density is 1000kg/m³
= 1.3kg/s/ 1000kg/m³
= 0.0013m³/s
C. Flow speead at 1
= 0.0013m³/s / (2 x 10-2m)²
= 6.5m/s
D.flow speed at 2
0.0013m³/s / (8x 10-2m)²
=1.63m/s
E. Gauge pressure at point 1
= 152+ 1/1000 ( 1.63)²- 6.5² + 1000( 9.8) ( 0-1.35)
= 119kpa