Under the Sea - Virtual Excursion

Transcription

1 Under the Sea - Virtual Excursion Welcome to the Maker Project Under the Sea Virtual Excursion. In this session, students will investigate the some of the difficulties and physical forces involved in exploring the ocean. This document provides information to prepare you and your students for the session. Included in this document are extension activities to follow up after the session to help maximise your students learning from our Virtual Excursion. What to expect Students will investigate how humans have tried to answer the big question of what is down in the deep. They will explore the concepts of pressure, light, and human innovations through the use of visual graphics, hands-on activities, demonstrations, film clips and games to experience why we know less about our deep ocean than we do about space. Runtime: 60 minutes Time Segment Description Teacher Notes 5 min BEFORE Audio Visual Check Teacher to adjust videoconference camera and microphone. Move the camera and zoom in/out to ensure the whole class is visible. 0-3 min Introduction Welcome to our Under the Sea Virtual Excursion min Biology of the Ocean Look at various animals that live in the oceans and their adaptions min Physics of the Ocean What happens as you go into the deep ocean? it s cold, dark with lots of pressure. If it is a single class session, make sure the microphone is NOT on mute (we ll be asking questions throughout the session), however if we have multiple schools dialling in, we will request which school should unmute and when. No action required. Teacher to pick students to answer questions and suggest marine life when prompted. Teachers to assist students with the water in a cup experiment. Instructions below.

2 25-30 min Understanding pressure What is pressure? Perform several experiments and demonstrations on pressure and its effects. Teachers to assist with asking questions and facilitating during experiments and demonstrations min The Deep Ocean What do we know about the Deep Ocean and how do we know it? Exploration of Buoyancy On screen experiment of what objects float and which sink min Build a Cartesian diver Demonstrates how buoyancy can change with pressure. No action required min Reflection and Conclusion No action required. Teacher to assist with discussion of what makes certain objects float or sink. Teacher to assist students with building the diver. The materials mentioned below should be organized prior to the session and the test tank set up. It is recommended to have a go at building prior to session. Information to assist facilitated activity Materials required for session Pressure Cup Experiment You will need (per student) Rigid Cup Plastic Plate Water Build a diver You will need (per group) 600mL (approximately) plastic bottle full of water with little to no air in the top A bendy straw cut to a smaller length (clear straws are better) Small paper clips (approximately 5) Cups filled with water Safety considerations Be wary of slip hazards when working with water, have paper towels or material nearby to dry drips and spills

3 Activity instructions Pressure Cup Experiment You will need: Per student Rigid Cup Plastic Plate Water Over the tank, students need to fill the cup with water and place the plastic plate over the top of the cup. Hold the card onto the cup firmly and turn it completely over. Take your hand away from the card and the card should stay on the cup. Tips: Get students to complete over a tub, just in case there is a spill Cups which have squishy sides aren t suitable for this experiment This can be done with postcards, but you will need a fresh postcard after it gets wet Build a diver You will need: Per group 600mL (approximately) plastic bottle full of water with little to no air in the top A bendy straw cut to a smaller length (clear straws are better) Small paper clips (approximately 5) Cups filled with water Materials

4 Step one: Insert the thicker part of the paperclip into the straw Step one Step two: Insert the thinner end of the paperclip into the other end of the straw Step two Step three: Test in cup of water, it should float at the top. Keep adding one paper clip at a time until it is only just floating on the top (you will need more paperclips if it is a big straw, and less if it is a small straw). If it sinks to the bottom, take a paperclip off! Step three Step three

5 Step four: Put the straw and paperclip contraption into the 600mL bottle and squeeze! It should sink to the bottom and when you stop squeezing, it will float again. Step four If you have a clear straw you can see the air bubble taking up less space!

6 Extension Activities Listed below are some optional activities to further your students learning. They utilise play and enquiry to explore the physics of buoyancy. Activity 1: Build a Deepsea Challenger You will need: Tank of water deep enough to sink an upright 600mL water bottle with some water left above it Per group (Image 1) 600mL plastic bottle (approximately) Weights (Eg. balloons filled with sand/rocks/rice) String Paper clips/bulldog clips Student should use this kit to construct a removable weight system for the Deepsea Challenger (the bottle). It needs to sink the bottle in an upright position. The weights need to be able to be removed easily in one movement, allowing the bottle to rise to the top again. The water level in the bottle is up to the students, as is what they want to experiment with to weight their Challenger. Activity 2: What is buoyancy (1) This activity is best run as a teacher demonstration to stimulate discussion. You will need: Three identical opaque watertight containers Water trough large enough to hold all three Method 1. Fill one container full of water, one a third/half full and leave the remaining container full of air without the students knowing. 2. Ask students what they think will happen when three apparently identical containers are placed in the water. 3. Once students have come to a consensus, place all three containers in the water, and lead a discussion about what the students observe, and what they believe to be happening.

7 Activity 3: What is buoyancy (2) This activity is best run as a teacher demonstration to stimulate discussion. You will need: One orange A clear tub filled with water (e.g. a fishtank) Method 1. Put the orange in the water. Does it float? Why? How can we test that? 2. Peel the orange, trying to keep the peel in one piece. 3. Put the peel in the water. Does it float? 4. Put the peeled orange in the water. Does it float? Activity 3: The smallest float This activity allows students to experiment with the effect of shape on buoyancy. They may work individually or in small groups. You will need (per group) A stick of plasticine A clear tub filled with water (e.g. a fishtank) Method 1. Divide the plasticine into 5 pieces of equal size (weight). 2. Mould each piece into different a different shape and place in the water. Which shapes are more stable? How much of the object is submerged? 3. Repeat with the aim to create a shape that will float with the smallest amount of submerged plasticine.

8 Buoyancy Explained Buoyancy is caused by a difference in fluid pressure at different levels in the fluid. Particles that are lower down are pushed down by the weight of all the particles above them (it may help to visualise the particles as small balls). The particles at the upper levels have less weight above them. As a result, there is always greater pressure below an object than above it, so the fluid constantly pushes the object upward. The force of buoyancy on an object is equal to the mass of the fluid displaced, or pushed aside, by that object. For example, if you submerge an empty 1 litre bottle in a bathtub, it displaces 1 litre of water. The water in the bathtub then pushes up on the bottle with 1 kilogram of force, the weight of 1 litre of water. If you submerge an object with a greater volume, it will be pushed upwards with more force because it displaces a greater volume of water. Floating, Sinking and neutral buoyancy Objects will float (be positively buoyant) when they displace an amount of water that weighs more than the object. An empty 1 litre bottle is lighter than the 1 litre of water that it displaces (equivalent to 1 kilogram of force), so it floats. Objects will sink (be negatively buoyant) when they displace an amount of water that weighs less than the object. What happens if you put a 5 kilogram weight into the 1 litre bottle? You haven t changed the volume of the bottle, but it now becomes heavier than the 1 litre of water it displaces (equivalent to 1 kilogram of force), so it sinks. Now imagine taking the 5 kilogram weight out of the 1 litre bottle and putting it in a 10 litre container. When you submerge the 10 litre container, it will displace 10 litres of water the equivalent of 10 kilograms of force pushing the container upward. This is greater than the weight of the container, so the container will float. When the density (the mass to volume ratio) of an object matches the density of the surrounding fluid, it will be neutrally buoyant, and remain where it is without rising or sinking. Adapted from:

9 Curriculum links Australian National Curriculum Online: - 4/5/2016 Science Science understanding Science as a Human Endeavour Science Inquiry skills Year 4 Year 5 Living things depend on each other and the environment to survive (ACSSU073) Forces can be exerted by one object on another through direct contact or from a distance (ACSSU076) Living things have structural features and adaptations that help them to survive in their environment (ACSSU043) Science knowledge helps people to understand the effect of their actions (ACSHE062) Science involves testing predictions by gathering data and using evidence to develop explanations of events and phenomena (ACSHE081) Compare results with predictions, suggesting possible reasons for findings (ACSIS216) With guidance, identify questions in familiar contexts that can be investigated scientifically and make predictions based on prior knowledge (ACSIS064) With guidance, pose clarifying questions and make predictions about scientific investigations (ACSIS231) Year 6 The growth and survival of living things are affected by physical conditions of their environment (ACSSU094) Science involves testing predictions by gathering data and using evidence to develop explanations of events and phenomena and reflects historical and cultural contributions (ACSHE098) Compare data with predictions and use as evidence in developing explanations (ACSIS218) With guidance, pose clarifying questions and make predictions about scientific investigations (ACSIS232) Compare data with predictions and use as evidence in developing explanations (ACSIS221)

10 Year 7 Year 8 Classification helps organise the diverse group of organisms (ACSSU111) Change to an object s motion is caused by unbalanced forces, including Earth s gravitational attraction, acting on the object (ACSSU117) Scientific knowledge has changed peoples understanding of the world and is refined as new evidence becomes available (ACSHE119) Sience knowledge can develop through collaboration across the disciplines of science and the contributions of people from a range of cultures (ACSHE223) Science knowledge can develop through collaboration across the disciplines of science and the contributions of people from a range of cultures (ACSHE226) Reflect on scientific investigations including evaluating the quality of the data collected, and identifying improvements (ACSIS131) Use scientific understanding to identify relationships and draw conclusions based on evidence (ACSIS130) Identify questions and problems that can be investigated scientifically and make predictions based on scientific knowledge (ACSIS139) Use scientific knowledge and findings from investigations to evaluate claims based on evidence (ACSIS234)