Definitions (Fluids)
What is the symbol and equation for density?
rho (p) = m/v
A hiker climbs from the bottom of death valley (85m below sea level) to the top of Mt. Whitney (4420m above sea level). What is the change in potential energy? (pg 348)
2872kJ
If a force acts on an object, is work completed? (Give an example to back up your answer)
No, forces that act on an object but do not change the objects kinetic energy or change the displacement of an object do not perform any work. (ex. pushing on a stationary object)
What is the formula for Kinetic energy?
1/2mv2
What is the formula for pressure?
P=F/A
Force/Area
You push a 50kg box across a frictionless surface with a force of 75N. It takes 15 seconds to move the box across the surface. What was your work and power?
Work = 3750 J
power = 250 watts
Is it possible to link kinematics and conservation of energy together?
Yes. Velocity is involved in both so it is possible to work between the two concepts.
Define work
Change in kinetic energy
What is the density of freshwater, seawater and standard atmospheric pressure?
Freshwater = 1000 kg/m3
Seawater = 1025 kg/m3
Patm= 1.01 x 105 Pa or 101kPa
How fast would an 80kg man need to run in order to have the same kinetic energy as an 8.0g bullet fired at a speed of 400 m/s? (pg 348)
4m/s
A roller coaster car rolls down a frictionless track reaching a speed (v) at the bottom. How high must you increase the height of the track if you want the car to go twice as fast at the bottom? (Pg 347)
The height needs to be four times the initial height.
What is energy conservation?
Kinetic energy initial+ Potential Energy initial = total energy available. The amount of energy remains constant.
What is gauge pressure?
Pg=P-Patm
What minimum speed does a 100 g puck need to make it to the top of a frictionless ramp that is 3.0m long and inclined at 20 degrees? (pg349)
4.48m/s
A cauldron, flask and hourglass are all .2 meters high. The cauldron can hold up to 5 L of water, the flask can hold 3 L of water and the hourglass can hold 1.5L of water. Rank the containers from highest to lowest based on the pressure at the bottom of the container. Assume that all containers are open.
P(cauldron)=P(flask)=P(hourglass)
What is theta in respect to work? (What angle does theta define?)
Theta is the angle between the force applied and the displacement of the object
What is the equation for static equilibrium in Fluids? (2 equations, one in terms of force, one in terms of pressure)
Fbottom=Ftop+weight of fluid
Pbottom=Ptop+(rho)gh
What are the three possible formulas for work?
w=FDcos(O)
w=mgd
w=-mgd