Finding Speed Rate

A climber is scaling a rock face. Two hours after starting his climb, he is at an altitude of 400 feet. After six hours, he is at an altitude of 700 feet. What is his average rate of change?

• 200 ft/hr

• 150 ft/hr

• 300 ft/hr

• 75 ft/hr

A balloon was 10 feet off the ground when it was the child who was holding it let it go. 5 seconds after that, the balloon was 20 feet off the ground. What was the balloon's rate of ascent?

• 10 feet per second

• 5 feet per second

• 2 feet per second

• 6 feet per second

A rocket is one mile above the earth 30 seconds after launch and five miles above the earth 2.5 minutes after launch. What is the rocket's rate of change in miles per second?

• 0.03 mi/sec

• 1.80 mi/sec

• 0.23 mi/sec

• 0.15 mi/sec

A chef weighed 145 lbs in 1986 and weighed 190 lbs in 2007. What was this chef's rate of change in weight?

• 2.14 lbs/year

• 11 lbs/year

• 4.1 lbs/year

• 0.24 lbs/year

Michael started a savings account. 4 weeks after starting this account, he had $300 dollars in it, and after 9 weeks, he had $400. What was the rate of change of money in his savings account over this time?

• $20/week

• $140/week

• $50/week

• $7.69/week

Which of the following is the correct equation to find rate of change?

• m=(y₂-y₁)/(x₂-x₁)

• m=(x₂-x₁)/(y₂-y₁)

• m=(y₂-x₂)/(y₁-x₁)

• m=(y₂+y₁)/(x₂+x₁)

True or False: "Slope" is just another word for rate of change. We tend to use this word when graphing the relationship between two quantities.

• True

• False

A rate is a number with a unit that...

• is a single quantity

• is a fraction of two different quantities

• does not exist

• is the square of a quantity

A convenience store opened for the day with 200 bags of Cheetos in stock. Five hours later, there were only 120 bags of Cheetos left.

How many bags of Cheetos was this store selling per hour, on average?

• 16

• 64

• 6

• 75

• 1 2/13 liters per hour

• 13/15 liters per hour

• 5 5/12 liters per hour

• 12/65 liters per hour