In: Physics
1. A contact lens and a sewing needle are pretty much the same weight. Why is one of these a lot more comfortable resting on your eye? Ah! ?? (everyday life)
2. Write what you remember about Pascal's principle without reading anything. Now go see how right you are!
3. How many 1/4 pound burgers do we need to stack on a table that is 1 meter by 1 meter to be the equivalent of 1 atmosphere? How many starving pygmy vampire bats would this feed for a light year?
4. A pipe contains an incompressible fluid. At some point along its path the pipe doubles in diameter. How does this affect the velocity of the fluid inside?
5. Picture of a cubic meter of water. How much do you think it weighs? Find the density of water then find the mass of a cubic meter of water and then multiply by gravity to see how close you were!
6. Do the same thing for a backpack of gold.
7. Which direction does a buoyant force point?
8. Compare the buoyant force and the weight for an object that sinks and floats.
9. What does the buoyant force for a submerged object depend on?
1) We know that pressure is inversely proportional to are of contact. Since the needle has less area its pressure on the eye will be more and due to more area of the lens it's pressure on the eye is less and hence the lens is more relaxing on the eye.
2) Pascal's law states that in a fluid at rest a pressure change in one part is transmitted without loss to every part of the fluid and to the walls of the container.
3) 1 pound = 0.454 kg
m = 1/4 pound = 0.1135 Kg
1 atm = 101325 Pa
F = PA
F = 101325 (1 m X 1m)
F = 101325 N
n(mg) = 101325
n = 101325/(mg)
n = 101325 /(0.1135X9.8)
n = 91095
n is the number of burgers
4) From equation of continuity
Av = constant
if diameter doubles then the velocity will reduce 4 times
5) density of water = 1 gm /cm3
mass of 1 cm3 of water = 1 g
7) The buoyant force points in an upward direction
8) the buoyant force is more than weight for an object which floats
the weight is more than the buoyant force for an object which sinks
9) the buoyant force for a submerged object does depend on the submerged volume of the object