Quiz 2: Levers

Question 1

A third-class lever increases the distance a load can be moved.

Answer 1

True

Question 2

Actual mechanical advantage and ideal mechanical advantage are not equal.

Answer 2

True

Question 3

Work output can never be greater than work input.

Answer 3

True

Question 4

Match these items: 1. a force causing rotation

Answer 4

torque

Question 5

Match these items: 2. highly efficient 1st class lever

Answer 5

equal-arm balance

Question 6

Match these items: 3. output divided by input

Answer 6

efficiency of lever

Question 7

What kind of lever is a bottle opener?

Answer 7

Second-class lever

Question 8

What kind of lever is a human forearm?

Answer 8

third-class lever

Question 9

A lever is four meters long. A load of 1,200 newtons is placed one meter from the fulcrum. The force on the 3 meter arm that will make it balance is _____ N. In order to lift the load above, a work input of 1500 N·m is applied. What is the efficiency of this lever? _____

Answer 9

400
80%

Question 10

A bar that turns on a fixed point is called a .

Answer 10

Lever

Question 11

A force of 30 N is executed to raise a rock weighing 90 N. The actual mechanical advantage is ______.

Answer 11

3.0

Question 12

In an actual lever system, like the one in this diagram, what does 8, Fi × di represent?

Answer 12

work input

Question 13

Which math ratio represents efficiency?

Answer 13

Output divided by input

Question 14

All machines are less than 100% efficient.

Answer 14

True

Question 15

What is the work input equal to?

Answer 15

F i × d i