1. Work and Force in Living Things
Get your lab notebooks, a pencil, and have a seat.
Moore MST Science
6/27/2018

2. Forces Change Things
Write in your notebook about ways that forces cause change.
Here are some helpful sentence stems to get you started
One way force causes change is ____________.
When a force is applied to a _______________, some changes I have noticed are ____________________.
Use complete sentences and write for about 2 minutes.
Moore MST Science
6/27/2018

3. Main Ideas Unbalanced forces cause motion. Work = force X distance.
Simple machines reduce force and increase distance.
Moore MST Science
6/27/2018

4. Force Force: The cause of motion (what causes objects to move)
Two major types of forces
Pushes
Pulls

5. Slow Motion Skateboard Crashes
While viewing the video, think about what forces are effecting the skateboarders.
Moore MST Science
6/27/2018

6. Measurement of Forces Newtons: SI (metric) unit of force Symbol: N
Measured by using a spring scale

7. Types of Forces
Balanced forces – all forces acting on an object are equal
There is NO MOTION
Unbalanced forces – one or more forces acting on an object are stronger than others
There is MOTION
Moore MST Science
6/27/2018

8. Unbalanced forces can = Work
When objects or living creatures are moving they can do work. But what is work?
In science class work is defined as: a force causing an object to move in the direction of the force applied
Effort doesn’t always equal work. I can push on the school building all day long, but little or no work will be done.
Moore MST Science
6/27/2018

9. What is Work?
Work can be calculated with the following formula:
W = F * d
Work equals force X distance
Work is measured in a metric unit called joules (J)
newtons
joules
meters
Moore MST Science
6/27/2018

10. What is Work? W = F * d Let’s solve an example problem:
If student “A” lifts a box of Christmas lights with 11 newtons of force 3 meters to the rooftop, how much work has he done?
A: W = 11 X 3 = 33 joules of work
Moore MST Science
6/27/2018

11. What is Work? W = F * d Let’s solve an example problem:
If student “A” pushes a box with 5 newtons of force 8 meters down the hall, and student “B” lifts a box with 12 newtons of force 2 meters to the top of a table, who has done the most work?
A: W = 5 X 8 = 40 joules of work
B: W = 12 X 2 = 24 joules of work
Moore MST Science
6/27/2018

12. What is Work?- a review Work = Force X Distance
Work is the product of a force applied
Causes movement in the direction of the force applied (no movement in the direction of the force = no work)
If I push against a house no work is accomplished…
W = F * d
Work is measured in joules; force in Newtons; distance in meters
Moore MST Science
6/27/2018

13. The Great Book Drag Work in lab-groups of 4 Share data between all 4
Each group of two will turn in their own paper
Measure the force required to lift a book .5 meters versus using a ramp to pull a book to the same height.
Be sure and follow directions!
Ask your lab partner before me!
Moore MST Science
6/27/2018

14. How simple machines make work easier
BIG SCIENCE IDEA:
Simple machines such as ramps, wheels, levers, etc. change the direction of our input force or allow us to use less force because they increase the distance
Remember: Work = force X distance
Moore MST Science
6/27/2018

15. Work and No Work
Contrast the situations of work and no work using an illustrated comic strip. Identify the forces at work in those situations.
Describe the force and work being done in the illustrations (if there is work being done).
Moore MST Science
6/27/2018

16. Main Ideas
Unbalanced forces cause motion. These forces are observable in the everyday life of organisms.
In plants the emergence of seedlings relies on unbalanced forces to allow the seedling to push its way to through the soil.
Force in the form of pressure allows green-stemmed plants to stand upright. This turgor pressure also keeps vegetables crisp.
Plants also respond to forces in the way they grow. Geotropism is the growth of a plant in response to gravity.
In animals, the contracting of muscles allows for movement of the organism. For example- the muscles of the heart create forces which cause the flow of blood through the circulatory system.
When a force is applied to an object and the object moves, work is done. In the physical sense, work is equal to the force multiplied by the distance.
Moore MST Science
6/27/2018

17. Plant Tropisms
Tropisms occur when plants respond to external stimuli. Tropisms are movements caused by a change in a plant’s growth pattern.
Tropisms can be negative or positive.
If the plant moves toward the stimulus, the tropism is defined as positive.
If the plant moves away from the stimulus, the tropism is considered negative.
Moore MST Science
6/27/2018

18. Plant Tropisms
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6/27/2018

19. Plant Tropisms
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6/27/2018

20. Plant Tropisms
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6/27/2018

21. Plant Tropisms
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6/27/2018

22. Plant Tropisms Let’s see some- “Plants in Motion”
Moore MST Science
6/27/2018

23. Thigmotrophism Phototropism Thigmotrophism
What type of tropism is shown in these pictures?
Phototropism
Geotropism
Thigmotrophism
Phototropism
Geotropism
Thigmotrophism
Moore MST Science
6/27/2018

24. Virtual Corn Geotropism Lab
Does gravity affect the emergence of a corn seedling?
We will record our hypothesis and information in our lab-books: work with lab partner
Moore MST Science
6/27/2018

25. Virtual Corn Geotropism Lab
Problem/Question: Does gravity affect the emergence of a corn seedling?
Research: Discuss with lab partner
Hypothesis: If , then …
Experiment: Draw the initial placement and appearance of the 4 corn seeds; explain procedure, etc.
Data & Conclusion: ???
Corn seed
Petri Dish
Moore MST Science
6/27/2018

26. Virtual Corn Geotropism Lab
Day 1:
Petri Dish
Corn seed
Moore MST Science
6/27/2018

27. Virtual Corn Geotropism Lab
shoot/stem
Day 4:
root
Moore MST Science
6/27/2018

28. Virtual Corn Geotropism Lab
shoot/stem
Day 4:
root
Moore MST Science
6/27/2018

29. Virtual Corn Geotropism Lab
Problem/Question: Does gravity affect the emergence of a corn seedling?
Research: Discuss with lab partner
Hypothesis: If , then …
Experiment: Draw the initial placement and appearance of the 4 corn seeds; explain procedure, etc.
Data & Conclusion: ???
Corn seed
Petri Dish
Moore MST Science
6/27/2018

30. Today’s Pre-AP Assessment
Work with your lab partner
Design your own science experiment to test a question about one of the types of tropisms that we have studied:
Geotropism
Hydrotropism
Thigmotropism
Phototropism
Remember the steps of the scientific method:
People really hate eating dirty carrots.
Problem, Research, Hypothesis, Experiment
Moore MST Science
6/27/2018

31. Main Ideas
Unbalanced forces cause motion. These forces are observable in the everyday life of organisms.
In plants the emergence of seedlings relies on unbalanced forces to allow the seedling to push its way to through the soil.
Force in the form of pressure allows green-stemmed plants to stand upright. This turgor pressure also keeps vegetables crisp.
Plants also respond to forces in the way they grow. Geotropism is the growth of a plant in response to gravity.
In animals, the contracting of muscles allows for movement of the organism. For example- the muscles of the heart create forces which cause the flow of blood through the circulatory system.
Moore MST Science
6/27/2018