5 Pressure and Density Flashcards
density =
![](https://s3.amazonaws.com/brainscape-prod/system/cm/276/107/454/q_image_thumb.png?1527358359)
density = mass / volume
How do you measure volume accurately when using a measuring cylinder?
Place measuring cylinder on a level surface
Read the volume at eye level and to the bottom of the meniscus
![](https://s3.amazonaws.com/brainscape-prod/system/cm/276/107/455/a_image_thumb.gif?1527358034)
What is the unit for density?
g/cm3 or kg/m3
Which orientation of the block below would create in a smaller pressure on a table?
![](https://s3.amazonaws.com/brainscape-prod/system/cm/276/107/457/q_image_thumb.png?1527358565)
First orientation
P = F/A
larger area in contact with the table,
for the same force,
therefore,
the pressure is lower
How can the volume of an irregular object be found using a measuring cylinder?
- Half fill measuring cylinder with water and read initial volume at eye level and bottom of the meniscus
- lower object into measuring cylinder- make sure that it is fully submerged and water level has not risen above the scale
- read final volume at eye level and bottom of the meniscus
- Volume of object = final volume - initial volume
![](https://s3.amazonaws.com/brainscape-prod/system/cm/276/107/458/a_image_thumb.jpg?1527359716)
The second object has half the mass but the same volume, How does its density compare to the first object?
![](https://s3.amazonaws.com/brainscape-prod/system/cm/276/107/464/q_image_thumb.jpg?1527444294)
density = mass / volume
if mass is double for the same volume, the density doubles.
density is proportional to mass
How could you find the density of a paperclip accurately?
- measure the mass of 50 paperclips on a balance
- half fill a measuring cylinder with water and record initial volume
- carefully add 50 paperclips and record final volume.
- calculate the volume by taking the difference
- Find density = mass / volume
What is a pascal?
the unit of pressure
1 Pascal = 1 Newton per metre square
How do you find the density from a mass vs volume graph?
calculate the gradient
gradient = rise/run = mass/volume
Explain what design feature makes a knife able to cut easily.
![](https://s3.amazonaws.com/brainscape-prod/system/cm/276/107/470/q_image_thumb.jpg?1527444820)
A sharp knife with a small surface area creates a greater pressure for the same force.
pressure = force/area
The knife will cut more easily
What is the unit for force?
Newton or N
Camels have adapted to walk effortlessly in the desert sand. Explain
![](https://s3.amazonaws.com/brainscape-prod/system/cm/276/107/473/q_image_thumb.jpg?1527359022)
Camels feet have a large surface area
P = F/A
A larger surface area for the same force results in lower pressure
How can the volume of an irregular object be measured accurately using a Eureka can?
- overfill eureka can with water and wait for water to stop dripping from the spout
- hang object from a string and slowly lower the object into the water until fully submerged
- Collect the water displaced in a measuring cylinder
![](https://s3.amazonaws.com/brainscape-prod/system/cm/276/107/474/a_image_thumb.jpg?1527359530)
Which orientation of the block below would create a larger pressure on a table?
![](https://s3.amazonaws.com/brainscape-prod/system/cm/276/107/475/q_image_thumb.png?1527358566)
Second orientation
P = F/A
smaller area in contact with the table for the same force, therefore, the pressure is higher
What is the unit for volume?
m3