What’s Goin’ On In Room 133

Archive for the ‘Weekend Word Problem’ Category

Speed Incarnate – Crossing the Room in One Second!

No, Colleagues, we’re not talking about The Flash (one of my favorites, by the way).  We are talking about the fastest human on the planet, Jamaican sprinter Usain Bolt, who seems to be able to crush records every time he lines up in the blocks.  At the World Championships last year he blazed through the 100 meter dash in an astonishing 9.58 seconds.  When you’re as old as I am (yes, 51!) THAT is a mind-boggling time.  (His 9.58 seconds, not my 51 years!)

So just how fast is that?  Can you calculate that in miles per hour (mph) ?  How about in kilometers per hour (kph)?  Tell you what – try doing it in kph first, then try converting that into mph?  Show me you’re work and let’s see what we get! 

Rock on!

On August 28, 1963, more than 250,000 demonstrators descended upon the nation’s capital to participate in the “March on Washington for Jobs and Freedom.”  The National Archives has a program and photo among the collection they call ”100 Milestone Documents” of American history.  The King Institute at Stanford University chronicles much of Dr Martin Luther King’s impact on the world, including his address at the march.  You can hear Dr King as he spoke to the crowd here.

Organizers had a lot to do to make it a success and as usual somebody had to do the math.  Suppose you were an organizer and you had to find bus transportation for a crowd of 250,000.  If each bus could hold 50 people, can you write an equation that would show the number of buses, b, that you would need to move the crowd?

What if there were more than 250,000 people in the crowd?  Can you wrtie an inequality that would show how many buses you need?  Can you graph that inequality?

Let c represent the number of people in the crowd.  How can you use that variable to show that there were at least 250,000 people there?  How about at least 250,000 and up to 500,000 – what would that inequaltiy look like?  (Hint: remember the lobsters in the lake in our Brain Pop video?)

Peace.

Colleagues, I am sure that you have seen the news about the devastating earthquake that hit the island country of Haiti this week.   Sadly, many thousands of lives were lost because it hit a region where more than 3 million people live.  The full extent of this tragedy will not be known for a long time.  Homes, schools, churches, roads, bridges – so many things that we take for granted in life were completely destroyed in seconds and an untold number of families had their lives ripped apart.  This is a very painful time for anyone with family or friends in the area – please be mindful.

Earthquakes are a natural phenomenon on this planet and there is nothing in our power that can stop one from happening.  But wouldn’t it be a good thing if we could at least predict when one is going to happen?  So that at least we can take steps to warn others?  And wouldn’t it be a good thing to build homes and buildings that would not collapse if and when an earthquake does occur?  Well, engineers are studying those very questions – and Math is helping them find answers.

Hear from those who are working on this problem.

See the Presidential Palace before and after the earthquake.

A quick look at what we know so far!

Not your regular Weekend Word Problem, is it?  True.  Sometimes we need to take a moment and put things in perspective.  A lot of times we ask “Why are we studying this?”  This is one of those times when I can tell you that there is only one reason to study math and that is to DO SOMETHING WITH IT TO MAKE LIFE ON THIS PLANET A LITTLE BETTER!  It doesn’t matter what scale you succeed on, Colleagues – the real success is that you try!  

And now for our problem:  Scientists determine the epicenter of an earthquake by measuring the time it takes for surface waves to travel between two places.  Surface waves travel about 6 kilometers per second through Earth’s crust.  (The “quick look” above shows you what this is like.)  Let’s say the distance between Los Angeles and Phoenix is about 600 kilometers.  First, write a multiplication equation to find how long it would take surface waves to travel from Los Angeles to Phoenix.  Then solve the equation.

The final speed of a falling object is found by using the expression v + 9.8t, where v is the speed when you begin timing and t  is the length of time the object falls.  Find the final speed when the object starts falling at 3 meters per second and falls for 2 seconds.  (Oh, we’re getting into it now, baby!)

UPDATED Dec 6, 2009:  And for a real easy one – check this out.   This problem has nothing to do with the speed problem above; this problem is “ripped from the headlines”!  It’s all about money, secrecy and good old government spending!  

Right now, President Barack Obama is having a tough time getting Congress to cough up billions (some would say trillions!) of dollars to take care of Americans at home.  Well, just over 200 years ago, President Thomas Jefferson had to “sneak around” to get Congress to make another major commitment as well, but what he had in mind was Americans pulling up stakes and leaving their homes for the Great Unknown. 

What was this about?  President Jefferson wanted Congress to fund the 8,000-mile expedition of Meriwether Lewis and William Clark.  It took (that is, the expedition took)  28 months to complete and it “provided the US government with its first glimpse of the vast lands that lay west of the Mississippi River”, according to the good folks at the National Archives.  And how much did President Jefferson want?  No less than the unholy sum of $2,500! 

Check out the SECRET LETTER from Pres Jefferson to Congress asking for the green!

So, the Word Problem is: How much did the Lewis & Clark Expedition cost per mile?  How much did it cost per month?  Do you think we got our money’s worth?  Rock on, colleagues!

Howdy, Colleagues!  Tell me, how do you evaluate 2² x  3³  x  4⁴ ?  Tell me what the steps are, and then evaluate the expression.  And love the beautiful cooks who gave you all that left-over turkey, you know?  Rock on!

Pluto’s maximum distance from Earth is about 4.6 billion miles.  One mile is equal to 5,280 feet.  Find the approximate maximum distance of Pluto from Earth in feet.  Then convert your answer to scientific notation and round your first factor to the nearest hundreth.  

(And may the Force be with you!)

It takes Zachery 2-3/4 hours to cut a lawn.  It takes Adam 3-1/8 hours to cut the same lawn.  How much faster is Zachery?

A 3-1/2 inch bolt is placed through a piece of wood that is 1-7/8 inches thick.  How much of the bolt is extending out?

A plumber needs to install a sink using pieces of pipe measuring 6-3/4 inches (read that as “six and three-quarters inches”), 10-2/3 inches, 5-1/6 inches and 3-1/8 inches. 

Find the total length of pipe needed to cut all the pieces.  (Rock on, Colleagues!)

Alex and 11 friends are celebrating Alex’s birthday.  His mom plans to distribute tokens for purchasing prizes to Alex and his friends.  Each person will receive 8 quarter tokens and 3 dollar tokens. 

Use the distributive property to describe this plan. 

(This is a GOOD one!)