Date: September 28, 2020
Topic: Sink and Float
Content: Any object placed in water has two forces acting on it. One is the force of gravity that pulls it downwards. The other is the force of the water pushing it upwards. The more water pushed away by an object, the harder the water pushes back. When the downward pull of gravity on an object (its weight) is equal to the upward force of the water pushing back on the object, the object floats. When the downward pull of gravity on an object (its weight) is greater than the upward force of the water pushing back on the object, the object sinks. Class Activity Answer the following open ended questions 1. What is a force? __________________________________________________________ ___________________________________________________________ ___________________________________________________________. 2. List briefly what happens to an object when force is applied to it. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ ________________________________________________________________ _________________________. The diagram below applies to questions 3 - 5 3. In this diagram, nobody is winning because the forces are _____________________________________________________________ ____________________________________________________________. 4. Nobody is winning because both teams are pulling with ___________________________ forces. 5. They are using ______________________________________ force in their hands and the rope, and ________________________________ force in thier feet into the ground. The diagram below applies to question 6 6. The two persons on the see-saw have the same weight and stand at equal distance from the ________________________________ ; so they make the see-saw _____________________________________. The diagram below applies to questions 7 - 8 7. Unbalanced forces causes _____________________________. 8. This see-saw does not balance because little Roy is ___________ than big Tim. The diagram below applies to question 9 9. The see-saw is now balanced because Roy moves closer to the _____________________________. Explore 1. Engage in an experiment. 2. The experiment is on page 39 of textbook, Mission Science Student’s Book 5.