10a. Work Problems

Question 1

What is the work formula?

Answer 1

work = rate x time

Question 2

If a machine works for 10 hours at a rate of 40 units per hour, what is the total work completed in that interval?

Answer 2

rate x time = work

40 u/hour x 10 hours = 400

Question 3

What is the rate at which an object is performing a task or job expressed as?

Answer 3

work / time

Question 4

The work rate is the __________ and not the _______

Answer 4

The work rate is the WORK PER UNIT TIME, and not TIME PER UNIT OF WORK

Question 5

What is the work rate of: Jackie who can paint 20 fences in 4 weeks?

Answer 5

Question 6

What is the work rate of: John who can fill 1 pool in 4 hours?

Answer 6

Question 7

What is the work rate of: Ying who can drink 3/4 gallons of milk in 2 hours?

Answer 7

Question 8

Answer:

Answer 8

Question 9

Solve:

Answer 9

Question 10

Solve:

Answer 10

Question 11

What is the equation linking work done by object 1 and work done by object 2, with total work?

Answer 11

Total work = work of object 1 + work of object 2

Question 12

Solve:

Answer 12

Question 13

In a problem where one object stops earlier, whilst the other continues, how would you express the time variable?

Answer 13

The object that stops work earlier’s time can be expressed as “x”

The objects that continues the work’s time can be expressed as “x + y”, with “y” being the additional time.

Question 14

Solve:

Answer 14

Question 15

Set up the equations and matrix:

Answer 15

Question 16

How would you calculate the fraction of the work a particular object did?

Answer 16

Question 17

Solve:

Answer 17

Question 18

How can you combine rates?

if one object takes x hours to complete, and another y hours

Answer 18

SIMPLE!

1/ x + 1/y

Question 19

Solve:

Answer 19

Question 20

How should you calculate the combined rate of a group, containing 3 different COMBINED rates?

Answer 20

1. ADD all the combined rate equations together
2. DIVIDE by a common factor to determine the combined rate of ALL the objects

Question 21

Solve:

Answer 21

Question 22

Solve:

Answer 22

Missing the final combination, this is important as it results in a common factor of 2 for each variable, and allows for the finding of the final solution.

Question 23

When two objects are working against one another, what should you do?

Answer 23

Subtract them!

The total task is the difference between their work values!

Question 24

Solve:

Answer 24

Question 25

If object 1 is "x" times faster than object 2, and object 2's rate is "r". What is the rate of object 1?

Answer 25

xr

Question 26

Solve:

Answer 26

Question 27

If object 1 takes "x" more minutes to complete a job compared to object 2, how could you express the rates?

Answer 27

Question 28

Solve:

Answer 28

Question 29

If object 1 takes "x%" more or less time compared to object 2, how would you express the rates?

Answer 29

Question 30

How could you solve this?

Answer 30

Question 31

Solve:

Answer 31