Question

Stacking pennies to the moon

1. Estimate how many pennies it would take to stack them from the earth to the moon. Give your answer in 1000s of dollars.
2. How much would all of these pennies weigh? Give your answer in tons.
3. Why did I ask you to estimate instead of giving an exact answer?

Be sure to state your assumptions and define your estimations. Include justification for these.

Use these facts (do not look up additional facts to help):

• Moon is about 238,900 miles (mi) away.
• Penny is 1.52 millimeters (mm) thick.
• There are 25.4 mm in an inch (in).
• There are 5,280 feet (ft) in a mile (mi).
• A penny weighs 2.5 grams (gm) or 0.088 ounces (oz)
• There are 16 ounces in a pound (LB)

What you should be paying attention to in order to earn a good grade:

• Of course, accuracy
• Units: You should have the unit of measurement for each measured value.
• Labels: You should label your steps; tell me what you are doing in each particular step. For example, one step might read, “I am finding how many pennies are in an inch.” I am not looking for a step by step explanation of operators (I multiplied, then I added), but the meaning of each step in the context of the problem.
• Make sure that you are using proper mathematical notation in the appropriate context. Be especially careful with the equal symbol: The expressions on either side of an equal symbol should be equal and have the same units.
• Use complete sentences in #3.
• Remember, this is about expression of a logical thought process with correct mathematical notation, so that anyone (even someone who does not know how to do this problem) could follow it and learn from it.

You might want to have someone else read it after you are done to make sure that your process is clear.

Answer 1

Given data:

Distance from earth to Moon is about 238,900 miles (mi) away

Thick ness of Penny is 1.52 millimeters (mm)

There are 25.4 mm in an inch (in)

There are 5,280 feet (ft) in a mile (mi)

A penny weighs 2.5 grams (gm) or 0.088 ounces (oz)

There are 16 ounces in a pound (LB)

Need to be found:

how many pennies it would take to stack them from the earth to the moon

Calculation:

in one feet =12 inches

12 inches=25.4 mm

In one mile = 5280 feet x 12 inchesx25.4mm= 1609344 mm

number of pennies are require to stack up one mile is =1609344/1.52mm=1058778

number of pennies are require to stack up from earth to moon=238900x1058778=252942064200

100 pennies = 1 doller

number of dollers are require to stack up from earth to moon= 2529420642

Answer in 1000 dollers =2529420.642

need to be found: How much would all of these pennies weigh? Give your answer in tons.

number of pennies are require to stack up from earth to moon=238900x1058778=252942064200

Weight of 252942064200 pennies = 252942064200x2.5 grams=6.323X10¹⁰ grams= 6.323X10⁷ kg

1000 kg= 1 ton

Answer in tons=6.323x10⁴ tons