Unit 10 Lessons

Cassie lives at the top of a hill. Which simple machine is the road to her house most like?

• inclined plane

• pulley

• screw

A jar lid has threads. These threads help hold the lid tightly on the jar. What simple machine is a jar lid?

• lever

• pulley

• screw

A bicycle is a compound machine. What are two simple machines found in a bicycle?

• wedge and screw

• lever and wheel-and-axle

• inclined plane and pulley

Why would a scientist say that riding a bike is called work?

• because a bike can help people get to and from a job

• because you need to push on the pedals to move the bike

• because the bike is a simple machine that makes work easier to do

Which job could you do with a pulley?

• pull a wagon up a hill

• split a log into two pieces

• lift a bucket of nails up to the roof

Which everyday item has a wheel-and-axle that makes work easier to do?

• a doorknob

• a hatchet

• scissors

lisa and Sara are on a seesaw. Sara moves closer to the center of the seesaw. What should Elisa do to lift Sara even more easily?

• push down harder

• bounce up and down

• move away from the fulcrum

Books have physical properties. Which of these are two physical properties of a school textbook?

• fuzzy and soft

• soft and sticky

• hard and rectangular

he three states of matter are solid, liquid, and gas. How is a solid different from a gas?

• A solid spreads out to fill its container. A gas has a definite shape.

• A solid takes the shape of its container. A gas spreads out to fill its container.

• A solid has a definite volume. A gas does not have a definite volume.

What will happen to an ice cube if you put it outside?

• It will not change

• It will change to a gas.

• It will change to a liquid.