Machines

What is the function of a pulley?

• To separate two objects

• To roll easily over a surface

• To lift or pull heavy weights

• To hold things together

Which of the following is a complex machine?

• Lever

• Screw

• Wedge

• Wheelbarrow

What does an inclined plane help us do?

• Rotate objects

• Move objects to higher or lower levels

• Make holes

• Roll faster

What force helps an airplane to rise into the air?

• Drag

• Weight

• Lift

• Gravity

What happens when a ship has no cargo?

• It rises and floats

• It becomes lighter than air

• It takes water in the tanks

• It lets water out of the tanks

What is the force that slows down an airplane?

• Thrust

• Drag

• Lift

• Weight

What is the purpose of the engine in a car?

• Create lift

• Reduce friction

• Produce thrust

• Store fuel

What shape helps air flow faster over an airplane's wings?

• Flat on both sides

• Curved on top and flat on the bottom

• Curved on both sides

• Flat on top and curved on the bottom

What is buoyancy?

• A force that pulls an object downwards

• The speed of an object in the air

• A force upwards in water

• A type of resistance

Which of these machines is used to separate two objects?

• Lever

• Pulley

• Wedge

• Screw