All categories

4 years ago

What is the average speed in km/h of a car that travels 400 km in 4.5 hours ?

Mathematics

2 answers:

Karo-lina-s [1.5K]4 years ago

6 0

Answer: 400/4.5=88.8

Step-by-step explanation:

Your answer would be 88.8km/per hour because dividing the distance by travel time will give you the per hour unit.

irinina [24]4 years ago

5 0

Answer:

88.8km/per hour

Step-by-step explanation:

You might be interested in

−4p+9=−5<br><br> Help a sister out plz

Lorico [155]

Answer: p=7/2=3.5

Step-by-step explanation:

Given

-4p+9=-5

Subtract 9 on both sides

-4p+9-9=-5-9

-4p=-14

Divide -4 on both sides

-4p/-4=-14/-4

p=7/2=3.5

Hope this helps!! :)

Please let me know if you have any questions

4 0

3 years ago

Read 2 more answers

Pls help I have a test today in math :( no 1 would help me pls try to help and its in 12:20 so I have a lot of time but pls help

DanielleElmas [232]

Answer:

C. he did not multiply the numerator by 2

Step-by-step explanation:

To find an equivlent fraction, you must multiply the numerator and denominator by the same thing.

3 0

3 years ago

Read 2 more answers

2x^2 / x^2 - y^2 - x^2 / xy - y ^ 2

Juliette [100K]

Answer:

2 - 2y^2 - x/y

Step-by-step explanation:

2x^2/x^2 = 2

and

x^2/xy = x/y

therefore

2x^2/x^2 - y^2 - x^2/xy - y^2

= 2 - y^2 - x/y - y^2

= 2 - y^2 - y^2 - x/y

= 2 - 2y^2 - x/y

6 0

3 years ago

You have been asked to design a can shaped like right circular cylinder that can hold a volume of 432π-cm3. What dimensions of t

rosijanka [135]

Answer:

$Height = 12cm$

$Radius = 6cm$

Step-by-step explanation:

Given

Represent volume with v, height with h and radius with r

$V = 432\pi$

Required

Determine the values of h and r that uses the least amount of material

Volume is calculated as:

$V = \pi r^2h\\$

Substitute 432π for V

$432\pi = \pi r^2h$

Divide through by π

$432 = r^2h$

Make h the subject:

$h = \frac{432}{r^2}$

Surface Area (A) of a cylinder is calculated as thus:

$A=2\pi rh+2\pi r^2$

Substitute $\frac{432}{r^2}$ for h in $A=2\pi rh+2\pi r^2$

$A=2\pi r(\frac{432}{r^2})+2\pi r^2$

$A=2\pi (\frac{432}{r})+2\pi r^2$

Factorize:

$A=2\pi (\frac{432}{r} + r^2)$

To minimize, we have to differentiate both sides and set $A' = 0$

$A'=2\pi (-\frac{432}{r^2} + 2r)$

Set $A' = 0$

$0=2\pi (-\frac{432}{r^2} + 2r)$

Divide through by $2\pi$

$0= -\frac{432}{r^2} + 2r$

$\frac{432}{r^2} = 2r$

Cross Multiply

$2r * r^2 = 432$

$2r^3 = 432$

Divide through by 2

$r^3 = 216$

Take cube roots of both sides

$r = \sqrt[3]{216}$

$r = 6$

Recall that:

$h = \frac{432}{r^2}$

$h = \frac{432}{6^2}$

$h = \frac{432}{36}$

$h = 12$

Hence, the dimension that requires the least amount of material is when

$Height = 12cm$

$Radius = 6cm$

3 0

3 years ago

Um I am very much stuck

lozanna [386]

Um. i’m pretty sure it’s just 30 feet

6 0

3 years ago

Read 2 more answers