# Physics

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Which of the following is not a fluid?
a. carbon dioxide
b. hydrogen
c. seawater
d. wood

D

Which of the following statements is not correct?
a. a fluid flows
b. a fluid has a definite shape
c. molecules fo a fluid are free to move past each other
d. a fluid changes its shape easily

B

Which of the following statemnents is true according to Pascal's principle?
a. pressure in a fluid is greatest at the walls of the container holding the fluid
b. pressure in a fluid is greatest at the center of the fluid.
c. pressure in a fluid is the same throughout the fluid
d. pressure in a fluid is greatest at the top of the fluid.

C

Tides are caused by
a. differences in the gravitational force of the sun at different points on Earth.
b. differences in the gravitational force of the moon at different points on Earth
c. differences in Earth's gravitational field strenght at different points on Earth's surface
d. fluctuations in the gravitational attraction between Earth and moon.

i think either B or D

thanks for the help!

• Physics -

Which of the following statemnents is true according to Pascal's principle?
a. pressure in a fluid is greatest at the walls of the container holding the fluid
b. pressure in a fluid is greatest at the center of the fluid.
c. pressure in a fluid is the same throughout the fluid
d. pressure in a fluid is greatest at the top of the fluid.

C None of the answers are right. If c were right, the pressure at the bottom of the ocean would be the same as near the surface. Here is Pascal's principle: Pressure applied to an enclosed fluid is transmitted undiminished to every part of the fluid, as well as to the walls of the container.
It is too bad c did not say pressure applied...

Tides are caused by
a. differences in the gravitational force of the sun at different points on Earth.
b. differences in the gravitational force of the moon at different points on Earth
c. differences in Earth's gravitational field strenght at different points on Earth's surface
d. fluctuations in the gravitational attraction between Earth and moon.

i think either B or D
B. The gravitationional attraction between Earth and Moon does not fluctuate measureable.

• Physics -

so what answer do you think i should pick for the Pascal's Principle one?

• Physics -

C is the closest to being correct in the pressure question. Pressure variations due to depth are usually small in hydraulic systems, compared to applied pressures. However, strictly speaking, all answers are wrong, as BobPursley has already said.

The sun also has a very strong effect on tides; it is about 1/3 of the effect of the moon. It is the reason you always have higher and lower tides when the moon is full or new

• Physics -

ok :)