Question

. Mr. Holmes just made an electric scooter and he wants to know if his scooter has broken the world record for speed which is 32.03 meters per second. Mr. Holmes recorded with his GPS a speed of 40.1 miles per hour.

• Convert the speed, showing all of your work, and determine if Mr. Holmes will be in the Guinness Book of World Records. Use the conversion factors of 1.00 inch = 2.54cm and 1.00 mile = 5280 feet.
• Form a conclusion, quoting data with the proper number of significant figures to break the news to Mr. Holmes.

Answer 1

• The speed recorded by Mr. Holmes is equivalent to 17.9 m/s (three significant figures).

• The conclusion is that Mr. Holmes's scooter has not broken the world word record.

Step-by-step explanation:

1. Convert the speed.

You can convert the speed recorded by Mr. Holmes, 40.1 miles per hour to meter per second following these steps:

a) Build the conversion factors:

• 1.00 inch = 2.54cm ⇒ 1 = 2.54 cm / 1 inch

• 1.00 mile = 5280 feet ⇒ 1 = 5280 feet / 1 mile

• 1 feet = 12 inch ⇒ 1 = 12 inch / 1 feet

• 1 m = 100 cm ⇒ 1 = 1 m / 100 cm

• 1 h = 3600 s ⇔ 1 = 1 h / 3600 s

b) Multiply 40.1 miles / h by the conversion factors in an appropiate form to show the cancellation of the units until getting m/s:

• 40.1 miles / h × (5280 ft/mile) × (12 in / ft) × (2.54 cm/in) × ( 1m / 100 cm) × (1 h / 3600 s) ≈ 17.9 m/s

2. Form a conclusion:

The proper number of significant figures on the speed recorded by Mr. Holmes is 3 (because 40.1 shows 3 significant figures), so you need to compare 17.9 m/s (recorded by Mr. Holmes) with 32.03 m/s (world record).

Evidently, 17.9 m/s < 32.03 m/s, so the conclusion is that Mr. Holmes's scooter has not broken the world record of speed.