Chapter 12 Flashcards
(14 cards)
What is the resistance of an object to any change in its motion?
Inertia
Mass/Volume=?
Mass/Volume=Density
Why do you weigh more in air rather than water?
The buoyant force of yourself pushes you up when you are in water.
What is the formula for work?
Force x Distance
What is the formula for power?
Work/Time
What is a joule?
The SI unit for work
What is a machine?
A tool that can reduce power used and work.
If someone is not moving but is holding 5000000000 pounds above their heads, are they performing work?
No, they are not in motion. Work = Force x Distance
What are the 6 types of simple machines?
Screw, Inclined Plane, Lever, Wheel and Axle, Pulley and Wedge.
If a machine has 99.9999% efficiency does 40,000 Joules of work, how much work do you do?
40,000J / .999999 = 40000.04J
How many simple machines do you need for a compound machine?
2
What is the formula for Potential Energy?
P.E.= Mass x Gravity x Height
What is the formula for Kinetic Energy?
K.E. Mass x Volume(2) x 0.5
What is the formula for Mechanical Energy
P.E. + K.E.
