Activity 1.6 "Time to Switch Gears"

What is the Gear Ratio ?

• The number of teeth on the driving gear divided by the number of teeth on the driven gear

• The diameter of the driving gear divided by the diameter of the driven gear

• The number of rotations of the driving gear divided by the number of rotations of the driven gear

• The speed of the driving gear in rpm divided by the speed of the driven gear in rpm

According to the learning material, if a gear turns 6,000 times in an hour, what is its rotational speed?

• 60 rpm

• 100 rpm

• 600 rpm

• 6,000 rpm

What is the relationship between the size of the gears and the resulting output speed of the system, as mentioned in the PLTW GATEWAY NOTEBOOK section?

• The output speed is always faster than the input speed

• The output speed is always slower than the input speed

• The output speed is always the same as the input speed

• The output speed can be faster, slower, or the same as the input speed, depending on the size of the gears

what can the size of a gear be measured by?

• Its diameter

• Its weight

• The number of teeth it has

• The material it is made of

What is the reduced gear ratio for the gear train with a gear ratio of 1:5 (12 teeth to 60 teeth)?

• 1:5

• 1:1

• 5:1

• 1:10

What is the reduced gear ratio for the gear train with a gear ratio of 3:4 (36 teeth to 48 teeth)?

• 3:4

• 4:3

• 1:1

• 3:2

What is the reduced gear ratio for the gear train with a gear ratio of 4:3 (48 teeth to 36 teeth)?

• 4:3

• 3:4

• 1:1

• 4:1

What is the reduced gear ratio for the gear train with a gear ratio of 5:1 (60 teeth to 12 teeth)?

• 5:1

• 1:5

• 10:1

• 1:1

How can you simplify a gear ratio to its simplest form?

• Multiply each value by the greatest common factor.

• Divide each value by the least common multiple.

• Divide each value by the greatest common factor.

• Add the greatest common factor to each value.

What do you notice about the setup for the gear ratio for the number of rotations versus number of teeth?

• The setup is exactly the same for both calculations.

• The gear ratio based on rotations is always larger.

• The gear ratio based on teeth is always smaller.

• The setup is reversed for calculations based on rotations versus number of teeth.