Vocabulary
The rate at which work is done.
What is power?
The work-energy principle states that the net work done on an object (by the net force( equals the change in ___________ energy of that object.
What is kinetic?
The equation used to solve this problem:
A spring-driven dart gun propels a 2-g dart. It is cocked by exerting a force of 10 N over a distance of 6.0 cm. With what speed will the dart leave the gun, assuming the spring has negligible mass.
What is:
Wdone to compress the spring = Fx = elastic potential energy = kinetic energy transferred to the bullet:
Fx = (1/2)mv2
The unit for work
What is the Joule (J)?
Fd Cos(theta)
What is the equation for work?
The ability to do work.
What is energy?
The law of __________________ states that energy can be transformed from one type to another, but the total energy remains constant.
What is the law of conservation of energy?
The equation used to solve this problem:
A 1000-kg car moving at 20 m/s hits an initially uncompressed horizontal spring with spring constant of 1.5 × 106 N/m. What is the maximum compression of the spring? (Neglect the mass of the spring.)
What is the law of conservation of Energy?
(1/2)mv2 + 0 = 0 + (1/2)kx2
The unit for Kinetic Energy.
What is the Joule?
WorkNet = Change in KE
What is the Work-Energy Principle
The energy of motion
What is kinetic energy?
Friction is a _______________ since the work it does depends on the path.
What is a non-conservative force?
The equation used to solve this problem:
A force of 20 N is applied horizontally to a 3.0-kg mass on a level surface. The coefficient of kinetic friction between the mass and the surface is 0.30. If the mass is moved a distance of 15 m, what is the change in its kinetic energy?
What is the work energy principle?
WNet = change in KE = Wpush + WFriction (note these will be different signs)
The SI unit for Power
What is the Watt (W)?
(1/2)kx2
____________ is done when energy is transferred from one object to another.
What is work?
Gravitational potential energy depends on the _____________ of the object above some reference level.
What is vertical height?
This is the equation to solve this problem:
At what rate is a 55.0-kg boy using energy when he runs up a flight of stairs 20.0-m high, in 9.00 s?
What is:
Power = energy transferred/time
Power = (mgy-0)/time
These are the SI base units that equal 1 Joule.
What is (kg m2)/s2 ?
KE2 + PE2 = KE1 + PE1
What is the Conservation of Mechanical Energy?
This is energy which is associated with forces that depend on the position or configuration of an object relative to the surroundings.
What is potential energy?
Elastic potential energy is proportional to the square of the ______________.
What is the distance compressed or stretched?
This is the equation to solve this problem:
A roller coaster passes position A, at a height of 9m at a velocity of 3m/s. It continues to position B along a U shaped track, 700.0 m in length. If the roller coaster only reaches a height of 4.0 m at position B, what is the average force of friction acting on the roller coaster?
What is:
KE1 + PE1 = KE2 + PE2 + Ffr(d)
This equals 1 Watt in SI base units.
What are (kg m2)/s3 ?
Change in KE + Change in PE
What is the Work done by a nonconservative force?