Pressure

Question 1

what is upthrust?

Answer 1

resultant force due to the difference in pressure between the top and the bottom surfaces of an object submerged in a fluid

Question 2

what is pressure due to?

Answer 2

pressure is due to weight. as depth increases, weight increases

Question 3

what is the equation for pressure?

Answer 3

pressure (Pa) = density (kg/m^3) x gravity (N/kg) x height (m)

Question 4

how does atmospheric pressure vary with height?(1)

Answer 4

as one moves higher into the atmosphere, there is a shorter column of air above a person so the weight of the air above a person decreases so pressure decreases

Question 5

how does atmospheric pressure vary with height?(2)

Answer 5

as one moves higher up into the atmosphere, the density of the air decreases so the number of particles decreases causing a decrease in the weight of the air above a person so a decrease in pressure

Question 6

what causes pressure?

Answer 6

air molecules colliding with other objects

Question 7

what is the earths atmosphere?

Answer 7

the thin layer of air that surrounds the earth

Question 8

why do liquids have pressure?

Answer 8

in any volume of liquid, there are vastly more particles so theres a greater pressure

Question 9

why do objects float?

Answer 9

when the weight is less than or equal to the upthrust

Question 10

why do objects sink?

Answer 10

if the weight is bigger than the upthrust