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3 years ago

Why use units with your number? Why is putting a unit with your number important?

2 answers:

5 0

Assume you need to know to what extent it will take you to get from your
house to some other place. You ask me, and I say, "It will take 5."
5 what? 5 minutes? 5 hours? 5 days?
We utilize numbers to speak to stuff on the planet. Some of the time it's simply
checking, e.g.,
I discovered 9 mushrooms today.
I discovered 18 yesterday.
So now I have 9 + 18 = 27 mushrooms.
Yet, some of the time we're utilizing numbers to speak to things that we measure,
like separations or weights or ranges:
I have a board 12 feet long.
I need to cut it into pieces 3 feet long.
I can cut it into (12 feet)/(3 feet for each piece) = 4 pieces.
We can utilize diverse methods for measuring something, e.g.,
I have a board 144 inches in length.
I need to cut it into pieces 3 feet long.
In the event that I simply isolate 144 by 3, without focusing on units, I get an
reply of 48. In any case, what does it mean? It's an indistinguishable issue from
some time recently, since 144 inches is an indistinguishable thing from 12 feet! So I would do well to
find a similar solution - 4 pieces, not 48. To find a similar solution, I have
to change my units:
I have a board 144 inches in length.
I need to cut it into pieces 36 inches long.
I can cut it into (144 inches)/(36 inches per piece) = 4 pieces.
So units are the means by which we ensure that our figurings about the world

jek_recluse [69]3 years ago

3 0

Answer:

Explanation:

When we measure a given physical quantity then after measurement we give the magnitude as well as unit along with the measurement

Here number gives the magnitude of the measurement what we did and unit gives an idea what unit is for the given measurement we used

Here unit is essential while we did any measurement because unit of the measurement may be different for different group of people but the quantity is always same when we compare them along with the unit

For example we know that

$1 ft = 12 inch$

here the numbers are different in two unit system but the quantity we compared is same.

so it is always essential to put units with all measurement to have complete idea of the quantity that is measured

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Total distance divided by total time

jasenka [17]

Explanation:

average speed is the total distance divided by total time

8 0

3 years ago

3.3 kg block is on a perfectly smooth ramp that makes an angle of 52° with the horizontal. (a) What is the block's acceleration

Alexus [3.1K]

Answer:

a) a = 7.72 m / s², N = 19.9 N and b) F = 25.5 N

Explanation:

To solve this problem we will use Newton's second law, let's set a reference system with an axis parallel to the plane and gold perpendicular axis. Let's break down the weight (W)

sin52 = Wx / W

cos52 = Wy / W

Wx = W sin52

Wy = w cos 52

Let's write them equations

X axis

Wx = ma

Y Axis

N-Wy = 0

N = Wy

a) Let's calculate the acceleration

a = W sin52 / m = mg sin 52 / m

a = g sin 52

a = 9.8 sin52

a = 7.72 m / s²

The force of the ramp is normal

N = Wy = mg cos 52

N = 3.3 9.8 cos 52

N = 19.9 N

b) For the block to move at constant speed the sum of force on the axis must be zero,

F - Wx = 0

F = Wx

F = mg sin52

F = 3.3 9.8 sin 52

F = 25.5 N

Parallel to the plane and going up

3 0

3 years ago

Which situations might cause two observers (A and B) to measure different frequencies for the same vibrating object? Select the

Alex787 [66]

We want to explain why two different observes may measure different frequencies for the same vibrating object.

We will see that the two correct options are:

Observer A is stationary and Observer B is moving.
Observer A and Observer B are moving at different speeds relative to each other.

Let's assume that the vibrating object is a guitar string. Thus, the string makes a noise, and from that noise, we can estimate the frequency at which the string vibrates.

Now there appears a really cool effect, called the Doppler Effect. It says that the apparent change of frequency is due to the motion of the observer or the source of the frequency (or both).

For example, if you move towards the vibrating string, the perceived frequency will be larger, and you will hear a "higher" sound.

While if you move away from the string, the opposite happens, and you will hear a "lower" sound.

Then the only thing that impacts in how we perceive the frequency is our velocity relative to the source.

So, why do observers A and B measure different frequencies?

The two correct answers are:

Observer A is stationary and Observer B is moving.
Observer A and Observer B are moving at different speeds relative to each other.

If you want to learn more, you can read:

brainly.com/question/17107808

6 0

2 years ago

Jeff's body contains about 5.46 L of blood that has a density of 1060 kg/m3. Approximately 45.0% (by mass) of the blood is cells

barxatty [35]

Answer:

The mass of blood is $m= 5.7876kg$

The number of blood cells is $N_t=1.04*10^{13}$

Explanation:

From the question we are told that

The volume of blood is $V_b = 5.46 \ L = \frac{5.46}{1000} = 0.00546m^3$

The density of the blood is $\rho_b = 1060 kg/m^3$

% of blood that is cell is = 45.0%

% of the blood that is plasma is = 55.0%

density of blood cell is $\rho_d = 1125kg/m^3$

% of cell that are white is = 1%

% of cell that is red is = 99%

The diameter of the red blood cell is = $7.5 \mu m = 7.5*10^{-6}m$

The radius of the red blood cell is $= \frac{7.5*10^{-6}}{2} = 3.75*10^{-6}m$

Generally the mass is mathematically represented as

$m = \rho_b * V_b$

Substituting value

$m = 1060 * 0.00546$

$m= 5.7876kg$

Mass of cell is $m_c$ = 45% of m

= 0.45 * 5,7876

= 2.60442 kg

The volume of cells is $V_c$ = $\frac{m_c}{\rho_d}$

$= \frac{2.60442}{1125}$

$= 2.315 *10^{-3} m^3$

The volume of white blood cell is $V_w$ = 1% of volume of cells

$= \frac{1}{100} * 2.315*10^{-3}$

$= 2.315*10^{-5}m^3$

The volume of a single cell is $V_s = 4 \pi r^3$

$= 4*(3.142) * (3.75*10^{-6})^3$

$= 2.21*10^{-16}m^3$

The volume of red blood cells is $V_r = V_c - V_w$

$=2.315*10^{-3} - 2.315*10^{-5}$

$= 2.29*10^{-3}m^3$

The number of red blood cell is $= \frac{V_r}{V_s}$

$= \frac{2.29 *10^{-3}}{2.21*10^{-16}}$

$= 1.037*10^{13}$

The Number of white blood cell is $=\frac{V_w}{V_s}$

$= \frac{2.315 * 10^{-5}}{2.21*10^{-16}}$

$= 1.04*10^{11}$

The total number of blood cells is $N_t= 1.037*10^{13} + 1.04*10^{11}$

$N_t=1.04*10^{13}$

6 0

3 years ago

Read 2 more answers

An object, initially at rest, is subject to an acceleration of 34 m/s^2. How long will it take for that object to reach 3400m ?

Norma-Jean [14]

Vf^2 = Vi^2 + 2ad
a= 34 m/s^2
Vi = 0 m/s
d = 3400m

Vf = 480.83 m/s

a=v/t
t=v/a
t=480.83/34
t=14.142 s

6 0

2 years ago