Work and Energy | Grade 8 Science DepEd MELC-Based Quarter 1 Module 3 Part 1 Work

[Music] what comes to mind when you hear the word work the word work has many meanings [Music] when people ask where do you work they refer to a job or employment when your teacher asks have you done your homework they refer to the tasks or activity you need to accomplish in physics work is an abstract idea related to energy when work is done it is accompanied by a change in energy when work is done by an object it loses energy and when work is done on an object it gains energy by the way if you still haven't watched our previous lessons you can pause this video and watch it first so you can easily understand a lesson here in the previous lessons we learned that force can change the state of motion of an object if an object is at rest it can be moved by exerting force on it if an object is moving it can be made to move faster or stopped by applying force on it in order to say that work is done on an object there must be force applied to it and the object moves in the direction of the force applied work is done if the object you push moves a distance in the direction towards which you are pushing it no work is done if the force you exert does not make the object move [Music] no work is also done if the object moves a distance in a direction that is not in the direction of the fourth supply take this man for example the force he uses to carry the backpack is upwards but he is moving in a different direction from the force applied work is done when the force applied to the object causes the object to have a displacement in the same direction as the force applied the symbol for work is a capital w the work done by a force can be calculated using this formula work equals to force times displacement as we have learned in the previous module the unit of force is kilogram meter per second squared or newton and the unit of displacement is meter hence the unit for work is the unit of force times the unit of displacement or newton meter otherwise known as joule [Music] the unit joule is named after the english physicist james prescott joel this is also a unit of energy one joule is equal to the work done or energy expended in applying a force of one newton through a distance of one meter let's try calculating for work done suppose you are pushing a chair with a 500 newton force along a seven meter aisle how much work is done in pushing the chair from one end of the aisle to the other so we have the formula work is equal to force times displacement the given force is 500 newton and the displacement is 7 meters so the work done is 500 newton times 7 meters which is equal to 3 500 newton meters or 3 500 joules try doing this simple activity play a bowling game roll a plastic or rubber ball along the floor to hit some empty plastic bottles or bowling pins is there work done in the ball what can a moving ball do the answer is yes you have done work on the ball the force you exerted in pushing the ball is in the same direction as the motion of the ball but then you did not continuously push the ball until it hit the empty bottles or bowling pins you just gave it a nudge and then it rolled forward the force exerted on the ball changed the ball's motion something was transferred to the ball causing it to move continuously that something is called energy the energy became the motion energy of the ball now let's wrap things up work is done when the force applied to the object causes the object to have a displacement in the same direction as the force applied that's all for now see you on our next video and don't forget to keep your minds busy if you like this video please subscribe to our channel and hit the notification icon for more videos like this

Channel: The Learning Bees

Views: 92,078

Keywords: The Learning Bees, Department of Education, DepEd, MELC-Based, Most Essential Learning Competencies, Science, Grade 8, Work and Energy, Work, Energy, Computation, Problem-Solving, Joule, Newton

Id: gv4cshx8Khg

Length: 5min 38sec (338 seconds)

Published: Sun Nov 01 2020