Answer:
31.321 rad/s
Explanation:
L = Tube length
A = Area of tube
= Density of fluid
v = Fluid velocity
m = Mass = 
Centripetal force is given by

Pressure is given by

The angular speed of the tube is 31.321 rad/s
Answer:
Hey shaikaadil700 !
<u> </u><u>Lubricating</u><u> </u> of rough surfaces reduces friction.
Explanation:
• Lubricating is the smoothening or polishing of the surfaces

Answer:
a. It always points perpendicular to the contact surface.
Explanation:
"Normal" means perpendicular. Normal forces are always perpendicular to the contact surface.
Answer:
I'm going to say b. gasoline is a chemical and when it combusts, it causes heat (thermal energy) and when the piston rotates because of the thermal expansion, you get mechanical force.