forces and matter

Question 1

what is an elastic material?

Answer 1

apply a force to a spring and it changes shape. release the force and the spring will go back to its original shape. objects that act like this are called elastic

Question 2

what is elastic deformation?

Answer 2

when an elastic project is out of shape temporarily

Question 3

what is inelastic deformation?

Answer 3

when a plastic shape is permanently out of shape

Question 4

what is hookes law?

Answer 4

hookes law is the relationship between force and extension

Question 5

what is the spring constant?

Answer 5

different objects have different spring constants this can be worked out using the hookes law equation

Question 6

what is the hookes law equation?

Answer 6

f = ke

f: force we apply
k: spring constant
e: extension

Question 7

what is extension?

Answer 7

how much the spring has stretched from its original length.

new length - old length = extension

Question 8

how does atmospheric pressure change with altitude?

Answer 8

the higher you go the lower the weight of the air above you therefore the lower the atmospheric pressure

Question 9

how is pressure related to force and area?

Answer 9

pressure = pressure x depth/height x density

IN FLUIDS

Question 10

how does the atmospheric pressure affect the pressure in the fluid?

Answer 10

when there is some pressure in the atmosphere, we add this to the fluid pressure and this would give us the total pressure of the fluid.

atmosphere pressure + fluid pressure (due to depth) = total pressure of the fluid

Question 11

what is pressure measured in?

Answer 11

n/m2 or pascal

1 pascal = 1n/m2

Question 12

what is the equation of pressure?

Answer 12

pressure (Pa) = force (N)
—————
surface area (m2)

Question 13

how does pressure increase with depth and density in fluids?

Answer 13

in fluids, the further down the point is that we are measuring, the more pressure it has. this is due to the weight of the rest of the fluid above the point we are looking at.

Question 14

what is upthrust?

Answer 14

the force of buoyancy and floating

Question 15

when does an object float (using upthrust)?

Answer 15

an object floats when it is the same or less dense than the water

Question 16

when will an object sink?

Answer 16

an object sinks when it is more dense than the water

Question 17

why does atmospheric pressure decrease when you go up a mountain?

Answer 17

there is less air particles so there is less weight so there is less pressure

Question 18

how does upthrust relate to displaced fluid?

Answer 18

if the weight of the object equals upthrust the object will float. this is because the object displaces a weight of fluid equal to its own weight. if weight is greater than upthrust the object will sink. tis is because the object is unable to displace fluid to its own weight.