Work & Force in Living Things Vocabulary

Work & Force in Living Things Vocabulary Seventh Science

WHAT IS FORCE? • Force is a push or a pull. • Force gives energy to an object, sometimes causing it to: 1. start moving 2. stop moving 3. change direction

PUSH

PULL

geotropism The way a plant reacts and responds to the force of gravity.

Phototropism • A plant’s response to light. It will bend toward the light.

Hydrotropism • A plant’s response to water—the roots will grow toward the water.

Thigmotropism • A plant’s response to touch.

Seed Coat • The hard outer covering of a seed which serves as protection.

Germination • The process in which the main root of the plant emerges from the seed.

turgor pressure A force exerted outward on a plant cell wall by the water contained in the cell’s vacuole. This force gives the plant rigidity and keeps it upright. • Plants that lose turgor pressure will wilt.

work • Occurs when a force is used to move an object over a distance • To calculate how much work is done: • Work = force(f) X distance (d) • The unit is called a JOULE.

force • A push or pull

Joule • Unit used to measure work • (a Newton meter)

Newton • The unit used to show force • (can be measure using a spring scale)

spring scale • Equipment used to measure force in Newtons

inclined plane • A simple machine that is a straight, slanted surface; a ramp The longer the incline plane the easier it is to move the object.

friction • A force that opposes motion between 2 surfaces that are touching • EXAMPLES • Sliding friction (ice skater) • Rolling friction (bowling ball rolling down the lane) • Fluid friction (pitcher throwing a ball)

gravity • The force of attraction between two objects Which famous scientist is responsible for the theory of gravity? ____________________ Hint- he also wrote the laws of motion.

Work & Force in Living Things Vocabulary