Question

vel = dist / time dist = time x vel time = dist / vel

1. a car travels 60 mph for 2 hours. how far does the car travel?
2. a high speed train in japan goes 250 miles 1.5 hours, what was its speed in miles per hour?
3. a bicycle rider journeys 60 miles at 20 mph. how long did it take?
4. a high school sprinter runs 100 m in 12.54 seconds. what is his speed?
5. a starter’s pistol goes off. it takes the sound of the gun.2915 seconds to reach the finish line 100 m away. what is the speed of sound?
6. the cheetah, the world’s fastest land animal, can run 75 mph. how far can the cheetah run in a minute?
7. chicken little runs back and forth warning that “the sky is falling down.” he runs for a minute. if the chicken runs at 5 m/s how much ground did the chicken cover?
8. a person standing at the equator moves with the earth in a circle at 1,000 miles per hour. if it takes earth 24 hours to make one complete turn on its axis, what is the distance around the equator?
9. the first automobile race took place in 1895 from chicago to evanston, a distance of 54 miles. the duryea car averaged 7 miles per hour. how long did it take?

Explanation:

Step1: Recall distance - speed - time formula

We use the formula $DIST = TIME\times VEL$ for questions asking for distance, $VEL=\frac{DIST}{TIME}$ for speed - related questions and $TIME = \frac{DIST}{VEL}$ for time - related questions.

Step2: Solve question 1

Given $VEL = 60$ mph and $TIME=2$ hours. Using $DIST = TIME\times VEL$, we have $DIST=2\times60 = 120$ miles.

Step3: Solve question 2

Given $DIST = 250$ miles and $TIME = 1.5$ hours. Using $VEL=\frac{DIST}{TIME}$, we get $VEL=\frac{250}{1.5}=\frac{500}{3}\approx166.67$ mph.

Step4: Solve question 3

Given $DIST = 60$ miles and $VEL = 20$ mph. Using $TIME=\frac{DIST}{VEL}$, we have $TIME=\frac{60}{20}=3$ hours.

Step5: Solve question 4

Given $DIST = 100$ m and $TIME = 12.54$ s. Using $VEL=\frac{DIST}{TIME}$, we get $VEL=\frac{100}{12.54}\approx7.98$ m/s.

Step6: Solve question 5

Given $DIST = 100$ m and $TIME = 0.2915$ s. Using $VEL=\frac{DIST}{TIME}$, we have $VEL=\frac{100}{0.2915}\approx343$ m/s.

Step7: Solve question 6

Given $VEL = 75$ mph. First convert 1 minute to hours, since 1 hour = 60 minutes, $TIME=\frac{1}{60}$ hours. Using $DIST = TIME\times VEL$, we get $DIST=\frac{1}{60}\times75 = 1.25$ miles.

Step8: Solve question 7

Given $VEL = 5$ m/s and $TIME = 60$ s. Using $DIST = TIME\times VEL$, we have $DIST=5\times60 = 300$ m.

Step9: Solve question 8

Given $VEL = 1000$ mph and $TIME = 24$ hours. Using $DIST = TIME\times VEL$, we get $DIST=1000\times24 = 24000$ miles.

Step10: Solve question 9

Given $DIST = 54$ miles and $VEL = 7$ mph. Using $TIME=\frac{DIST}{VEL}$, we have $TIME=\frac{54}{7}\approx7.71$ hours.

Answer:

1. 120 miles
2. $\frac{500}{3}\approx166.67$ mph
3. 3 hours
4. $\approx7.98$ m/s
5. $\approx343$ m/s
6. 1.25 miles
7. 300 m
8. 24000 miles
9. $\frac{54}{7}\approx7.71$ hours