1. Forces in everyday life

2. Gravity Is the force of attraction between objects that have mass.
Mass is a measure of the amount of “stuff” in an object. All objects have mass.

3. Geotropism “geo”-earth
“tropism”- movement or response to external stimuli.
Geotropism or Gravitropism is the growth of the parts of plants with respect to the force of gravity

4. Geotropism cont..
The force of gravity cause the roots of the plant to grow towards the Earth’s core where gravity is strongest and the stem or leaves to grow up towards the sun.
The roots are growing in a positive direction, while the stem or leaves are growing in the negative direction with respect to the force of gravity.

5. Foldable Fold a piece of paper in half, hot dog style
Draw root, seed, and stem
Cut between soil level
Top half: stem grows up, opposite to the force of gravity (negative force)
Bottom half: roots grow downwards towards Earth’s center, where gravity is strongest (positive force)

6. Questions What would happen if there was no gravity?
How the plants grow (roots and stem)?
What if there was no sunlight?
EXIT
Is gravity doing work on plants? How?