4c-Work and power Flashcards
What is work done?
A: Work is done when a force is applied to an object and moves it in the direction of the force.
How is work done related to energy transfer?
Work done on an object transfers energy to it. The energy gained equals the work done.
Example: Pushing a car transfers energy to it, increasing its kinetic energy.
What is gravitational potential energy (GPE)?
A: GPE is the energy stored in an object due to its position in a gravitational field.
Example: Lifting a book onto a shelf increases its GPE.
What is kinetic energy?
A: Kinetic energy is the energy of an object due to its motion.
Example: A moving car has kinetic energy, which increases with speed.
How are gravitational potential energy, kinetic energy, and work related?
A: The conservation of energy principle states that energy is transferred between stores:
When an object falls, GPE converts to KE.
When an object is lifted, KE converts to GPE.
Work done on an object increases its energy store.
Example: A roller coaster at the highest point has maximum GPE, which converts to KE as it descends.
Q: What is power?
A: Power is the rate of doing work or the rate at which energy is transferred.
Example: A powerful car engine transfers energy at a higher rate, making the car accelerate faster.
Practical: Investigating Work and Power
Measuring Work Done in Lifting an Object
Method: Use a Newton meter to measure force and a ruler to measure height.
Observation: Calculate work done using .
Practical: Investigating Work and Power
Measuring Power Output of a Student
Method: Measure a student’s mass and time taken to run upstairs.
Observation: Use and to determine power output in watts.
