6.3 Simple Machines

Why do people use simple machines in their daily lives?

• To make your works more difficult

• To make work easier

• To create more complex machines

• To increase the amount of force needed

How do rollers help us move objects?

• They reduce the force needed by decreasing friction

• They make objects heavier

• They are only used on smooth surfaces

• They increase friction

What happens when the slope of an inclined plane is gentler?

• More force is needed

• It becomes steeper

• No effects

• Less force is needed

What are the three main components of a lever?

• Arm, effort, and distance

• Base, load, and handle

• Fulcrum, load, and effort

• Load, arm, and force

Which of the following items commonly uses gears?

• A paper clip

• A book

• A pencil

• A watch

To reduce force, We should choose a gentler slope (較平緩的斜坡） when we ride the bicycle up to the mountain.

• True

• False

When a gear set rotates, two connected gears will rotates in the ____________ direction

• same

• opposite

When two gears are connected by a chain, they rotate in the ________ direction, example like bicycle.

• same

• opposite

What happens when the effort arm is longer than the load arm?

• making it harder to lift the load.

• making it easier to lift the load.

What kind of simple machine does the tool in the picture use?

• Lever

• Inclined plane

• Gears

• Rollers