P1 - Conservation and Dissipation of Energy Flashcards
What is energy?
Ability to do work.
Give some examples of energy stores.
Chemical, Thermal and Nuclear.
What is the Law of Conservation of Energy?
Energy cannot be created or destroyed.
Give some examples of energy pathways.
Waves, Mechanical, Heat.
Explain the changes of energy stores for a battery-powered torch.
The battery has a chemical energy store which is transferred via electric current, the energy is transferred into a light energy store but also a thermal energy store.
State the changes in energy store when a ball falls in the air.
The gravitational potential energy when the ball is held up high transfers via the mechanical pathway into a kinetic energy store.
Give a step-by-step method on how to investigate energy loss in pendulums.
Hang the pendulum off a perpendicular clamp to the desk stand, drop the pendulum from a designated height, then record the height it swings back to. Repeat this with different initial heights.
Define work.
Work is a measure of the transfer of energy as a object is being displaced.
What is the equation linking Work, Force and Distance together (with units).
Work(J) = Force(N) x Distance(m)
What is the equation for speed regarding Work.
Speed = Work / Distance
How do we find out our lifting force.
It is the same as the weight of the object (mass x 10(or 9.8)
How does friction affect the work done.
Friction causes resistance in an object’s motion, therefore there would be more energy needed to move an object at the same distance if there was no friction.
Why do brake pads get super hot?
Much kinetic is transferred to a heat energy store
What is the equation for gravitational potential energy?
E = mass * gravitational field strength * height
What is the equation for Kinetic energy?
Energy = 1/2 * mass * velocity^2
