Fluid and Solids

Question 1

Is solid water more dense or is liquid water more dense?

Answer 1

Liquid water

Question 2

True or False. Balloons rise when their total density is less than that of the air surrounding them.

Answer 2

False, helium balloons float and their density if greater than air. It’s when the weight of the object is less than buoyant force that tells you it will float.

Question 3

In a pipe, is the flow speed the same throughout the pipe?

Answer 3

Nope. Flow speed is like velocity and that’s not the same everywhere.

Question 4

In a pipe, is the flow rate the same throughout the pipe?

Answer 4

Yep. Flow rate is equal to Area*velocity

Question 5

Will an object with more mass but same volume as another object sink faster in a non-viscous fluid?

Answer 5

Yes, because buoyant force impedes downward acceleration of a greater mass less than it does a lesser mass. So the acceleration of the smaller mass will be greater. Use equation “mg - pVg = ma” and convert to “a = g - (pVg)/m” and notice that as mass increases, the subtracted amount is less so the final acceleration will be greater.

Question 6

If four different objects with the same density are placed in a liquid and they all have different amounts of volume displaced, which object will have the largest mass?

Answer 6

The one that displaces the most volume, because we know, the volume submerged is proportional to the volume of the object, and mass = density * volume, so as volume increase, then mass should increase too.

Question 7

If there is a really big container of juice, how can we increase the speed of the juice coming out of the tube?

Answer 7

Decrease the diameter of the tube where the juice exits.

Add more juice to the container