All categories

2 years ago

when heated an iron bar expands by 0.2 %.if the increase in length 1 cm, what is the original length of the bar?

Mathematics

1 answer:

gregori [183]2 years ago

5 0

0.2% = 2/100

increase amount over the whole amount

If the increase length is 1cm and you are looking for the whole amount

2/100 = 1/x

Cross multiply
2x = 100
x = 50 cm is the original length of the bar

Checking you answer,
0.2% of 50 is 0.02 × 50 which is 1 so the answer is correct.

The original length of the bar is 50 cm.

You might be interested in

Joe hypothesizes that the students of an elite school will score higher than the general population. He records a sample mean eq

Andrew [12]

Answer:

The test to be used is the right tailed test.

Step-by-step explanation:

The type of test joe should do would be a right tailed test. This is because;

A right tailed test which we sometimes call an upper test is where the hypothesis statement contains the greater than (>) symbol. This means that, the inequality points to the right. For example, we want to compare the the life of batteries before and after a manufacturing change.

If we want to know if the battery life of maybe 90 hours would be greater than the original, then our hypothesis statements might be:

Null hypothesis: (H0 = 90).

Alternative hypothesis: (H1) > 90.

In the null hypothesis, there are no changes, but in the alternative hypothesis, the battery life in hours has increased.

So, the most important factor here is that the alternative hypothesis (H1) is what determines if we have a right tailed test, not the null hypothesis.

Thus, the test to be used is the right tailed test.

7 0

2 years ago

Phil has 3 times as many rocks as Peter. Together, they have 48 rocks. How many more rocks does Phil have than Peter?

Ivan

Let x = the number of marbles for Phil
Then 3x = the number of marbles for Peter
Together they have 3x+x=48 or 4x=48 and x=12
So Phil has x = 12 marbles and Peter has 3x, let x = 12, 3(12) = 36 marbles.
Peter has 24 more marbles than Phil.

3 0

2 years ago

Read 2 more answers

A car with 15 gallons of gasoline drives 420 miles until the tank is empty. Write a linear equation that describes the amount of

DedPeter [7]

Answer:

g = 15 - m/28

Step-by-step explanation:

let g = gasoline

let m = miles

g = 15 - m/28

since you can drive 420 miles with 15 gallons of gas, you can drive 28 miles with one gallon (= 420/15 = 28)

e.g.

you drive 100 miles, then you will have:

g = 15 - 100/28 = 15 - 3.57 = 11.43 gallons of gas left

you drive 240 miles:

g = 15 - 240/28 = 6.43 gallons

4 0

2 years ago

Let P be a point not on the line L that passes through the points Q and R. The distance d from the point P to the line L is d =

Goshia [24]

Answer:

Distance from point (0,1,1) to the given line is zero.

Step-by-step explanation:

Given parametric equations of line,

x=2t, y=5-2t, z=1+t

To find distance from (0,1,1), we have to eliminate t from above equations so that,

$y=5-2t=5-x\implies x+y=5=4+1=4+z-t=4+z-\frac{1}{2}x$

$\implies 3x+2y-2z-8=0\hfill (1)$

whose direction ratioes are (l,m,n)=(3,2,-2) and distance fro point (a,b,c)=(0,1,1) is given by,

$\frac{al+bm+cn}{\sqrt{l62+m^2+n^2}}=\frac{(3\times 0)+(2\times 1)+(-2)(1)}{\sqrt{3^2+2^2+(-2)^2}}=\frac{0+2-2}{\sqrt{17}}=0$

Distance between point (0,1,1) and (1) is zero. That is point 90,1,1) is lies on the line (1).

8 0

2 years ago

Aron has a bag of marbles that contains three red (R) marbles, four green (G) marbles, and three blue (B) marbles. 3 red marbles

jeyben [28]

Answer:

3/25

Step-by-step explanation:

3 red marbles, 4 green marbles, and 3 blue marbles = 10 marbles

P(green) = number of green / total = 4/10 = 2/5

We replace it

3 red marbles, 4 green marbles, and 3 blue marbles = 10 marbles

P(red) = number of red / total = 3/10

P(green, replace,red) =2/5*3/10 = 3/25

4 0

2 years ago