Bell Ringer 9/23/16 When a seedling emerges upright from the soil, which force is it overcoming? A. Gravity B. Magnetism C. Repulsion D. Heat

Partner Discussion Explain what causes a plant’s stem to grow upward and its roots to grow downward, even when the plant is turned on its side or upside down. Be sure to include the force that causes this. Correct answer will include the following elements - Geotropism occurs when a plant turns toward or away from the pull of gravity. A plant’s stem grows away from the force of gravity and it’s roots grow toward the force of gravity. Even when a plant is turned on its side, it still responds to the force of gravity, with the stem growing up and the roots growing down.

Partner Discussion Explain how the force of turgor pressure causes a plant to return to its upright position after a period of dehydration. Correct answer will include the following elements - Water within a plant cell exerts a force against the cell wall called turgor pressure. Turgor pressure allows a plant to maintain a strong, upright position. When a plant does not get the water that it needs, the cells lose their shape and the plant wilts. When a wilted plant is watered, the plant’s cells will again become rigid as the water exert a force against the cell wall. The plant’s leaves and stems will become firm and tall once again.

Monday 10/3/16 A student lifts an object to a certain height with no tools. Another student lifts the same object to the same height using a ramp. Which of the following remains the same for both students? A. The friction acting against the object B. The amount of work done on the object C. The horizontal distance the object travels D The force used to move the object

Tuesday 10/4/16 When an object is lifted directly from the ground rather than moved with an inclined plane, which of the following will be increased? A. The mass of the object B. The work done on the object C. The force needed to move the object D. The amount of friction acting on the object

Wednesday 10/5/16 All of the following describe situations in which work is done by an organism EXCEPT for which situation? A. A bird carries a worm to its nest B. A squirrel hides nuts in a tree C. Ants bring crumbs into their home D. Leaves decompose on the forest floor

Partner Discussion What conclusion might you draw if distance increases and force decreases? The amount of work should remain the same.

Partner Discussion Thinking back to the work lab, as you measured work and collected data, where might you have errors? Some places errors may occur might be in the spring scale measurement or by moving the object incorrectly. The ramps had different surfaces that could have increased or decreased the amount of friction compared to the other surfaces.

Thursday 10/6/16 You have five minutes to study for the test.