Grade 8 Science – Mechanical Systems Unit Test

A simple machine is called a simple machine because it is (a)  

• easy to operate
• complex to operate
• made of one basic machine
• a machine that does simple work

Simple machines were developed to:

• Reduce government pressure

• Make life easier

• Create jobs

• Make tasks more complex

The point around which a lever rotates is the:

• load force

• fulcrum

• wedge

• effort force

Best simple machine for moving a flat rock into a lorry:

• Long ramp

• Short ramp

• Large wedge

• Wheel and axle

A disadvantage of an inclined plane is:

• Less force is needed

• Greater distance must be covered

• One-direction use only

• Must be turned further

A disadvantage of a wedge is:

• Greater force over longer distance

• Greater distance movement

• One-direction use

• Must turn further

All are complex machines EXCEPT:

• Bicycle

• Bottle opener

• Drill

• Circular saw

A linkage in a bicycle functions to (a)  

• Transfer energy
• slow the machine down
• change the direction of motion
• Both a and b

Gears that increase the speed of rotation in a device are called

• Driving gears

• Driven gears

• Reducing gears

• Multiplying gears

To increase speed in a gear system:

• the driving gear must be smaller than the driven gear

• the driving gear must be larger than the driven gear

• the driving gear must be the same size as the driven gear

• None of these