1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
irga5000 [103]
3 years ago
10

If you run for 0.4 hours at 7 mph, how fast should you walk during the next 0.8 hours to have the average speed of 5 mph?

Mathematics
1 answer:
Fantom [35]3 years ago
4 0

Answer:

4 mph

Step-by-step explanation:

The average speed of an object is given by the total distance covered by the time taken:

v=\frac{d}{t}

where

d is the total distance covered

t is the time taken

in the first part, the person runs for 0.4 hours at a speed of 7 mph, so the distance covered in the 1st part is

d_1 = v_1 t_1 = (7)(0.4)=2.8 mi

Then the distance covered in the second part is d_2, so the total distance is

d=2.8+d_2 (1)

The total time elapsed is 0.4 hours (first part) + 0.8 hours (second part), so

t=0.4+0.8=1.2 h

So we can write the average speed as

v=\frac{2.8+d_2}{1.2} (1)

We want the average speed to be 5 mph,

v = 5 mph

Therefore we can rearrange eq.(1) to find d2:

d_2 = 1.2v-2.8 = (1.2)(5)-2.8=3.2 mi

And therefore, the speed in the second part must be

v_2=\frac{d_2}{t_2}=\frac{3.2}{0.8}=4 mph

You might be interested in
A deck of cards contains RED cards numbered 1,2,3 and BLUE cards numbered 1,2,3,4,5,6. Let R be the event of drawing a red card,
Tatiana [17]

Answer:

e. R′

Step-by-step explanation:

Let the Sample Space be a universal set consisting of 3 red  and 6 blue cards. Then the event of  of getting 4 blue cards will be given

R complement = R` = Universal Set minus Red cards will give blue cards.

a. R OR O

It cannot be this option because we need 4 blue card

b. B AND O

It cannot be this choice as well because 4 is not odd.

c. R OR E

4 is even but we need blue

d. R AND O

Red and odd is again not required

e. R′  = It  will give our required result.

f. E′= 4 is even if it is complemented it cannot be obtained and will be left out.

5 0
3 years ago
Ann is participating in a 4-day cross country biking challenge. She biked for 65, 69, and 45 miles on the first three days. How
GenaCL600 [577]

Answer:

the answer is 69

hope i helped <3

Step-by-step explanation:

6 0
2 years ago
2/3 of 1/2 <br> What is the answer.
Deffense [45]

Answer:

1/3 or 0.33333333333_

Step-by-step explanation:

7 0
3 years ago
Read 2 more answers
A triangle has one angle that measures 40 and another that measures 38. What is the measure of the triangles third angle
mr_godi [17]

Answer:

102°

Step-by-step explanation:

that's the answer because 40+ 38 = 78. then 180- 78 = 102. Remember that in tringles, all three angles should add up to 180°

4 0
3 years ago
Pls just look at the pic to find the question
kvasek [131]
If you count the squares, you will see that there is 3 squares or units between Q and R and 7 squares or units between P and Q
Answer is D.
5 0
3 years ago
Other questions:
  • 645 divided by 43 I need help please
    8·2 answers
  • If a rectangle was rotated about the y-axis, like the one shown below, what would be the resulting three-dimensional shape? An i
    5·2 answers
  • In sm.smiths class 75% of the students are girls.there are 18 girls in the class.what is the total number of students in ms.mith
    14·2 answers
  • Which of the following expressions represents the GCF of 91x 2 y and 104xy 3?
    5·2 answers
  • 18.) Which of the following is 6x²/27x simplified?
    14·1 answer
  • 30 POINTS PLEASE HELP
    7·1 answer
  • Help meeeeeeeeeeessss​
    8·1 answer
  • Liz got home from school at 4:33. She decided to bake muffins as an after-school snack. It took Liz 55 minutes to prepare and ba
    7·1 answer
  • Help this is due a few minutes
    7·1 answer
  • PLEASE HELP AS SOON AS POSSIBLE
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!