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
blondinia [14]
2 years ago
10

The temperature of a solution will be estimated by taking n independent readings and averaging them. Each reading is unbiased, w

ith a standard deviation of σ = 0.5°C. How many readings must be taken so that the probability is 0.90 that the average is within ±0.1◦C of the actual temperature? Round the answer to the next largest whole number.
Physics
1 answer:
Viktor [21]2 years ago
3 0

Answer:

68 readings.

Explanation:

We need to take this problem as a statistic problem where the normal distribution table help us.

We can start considerating that X is the temperature of the solution, then

0.9 = P(|\bar{x}-\mu|

0.9 = P(\frac{|\bar{x}-\mu|}{\frac{\sigma}{\sqrt{n}}}

0.9 = P(|Z|

For a confidence level of 90% our Z_{critic} is 1.645

Therefore,

\frac{0.1}{\frac{\sigma}{\sqrt{n}}} = 1.645

Substituting for \sigma = 5 and re-arrange for n, we have that n is equal to

n=(\frac{1.645\sigma}{0.1})^2

n=\frac{(1.645)^2(0.5)^2}{0.1^2}

n=67.65

n=68

We need to make 68 readings for have a probability of 90% and our average is within 0.1\°\frac

You might be interested in
At the bottom of a large cylindrical tank filled with fresh water the gauge pressure is 11.6 psi. What is the height (in feet) o
Art [367]

Answer:

8.19m

Explanation:

Parameters given:

Pressure, P= 11.6 psi = 79979.185 Pa

Gauge pressure is given as:

P = h*d*g

=> h = P/(d*g)

Where

h = height of tank

d = density

g = acceleration due to gravity

Density of water = 997 kg/m³

Therefore, the height of the tank is:

h = 79979.185/(997 * 9.8)

h = 8.19m

3 0
3 years ago
EASY BRAINLIEST PLEASE HELP!!
Soloha48 [4]

Answer:

Solution given:

frequency[f]=x

velocity[V]=15000m/s

wave length=59m

we have

wave length=\frac{V}{f}

59m=\frac{15000}{x}

x=\frac{15000}{59}=254.Hz

frequency=254Hz

7 0
3 years ago
Read 2 more answers
Which change would decrease the total current, I, flowing through this circuit?
iren [92.7K]

Answer:

A. Increasing the voltage of the battery

Explanation:

The relationship between voltage, V, current, I and resistance, R, is given as follows;

V = I × R

∴ I = V/R

From the above relationship, the current flowing in the circuit is directly proportional to the voltage of the battery, and inversely proportional to the resistance, 'R', of the circuit

Therefore, increasing the voltage, 'V', of the battery, increases the total current, 'I', flowing in the circuit.

7 0
3 years ago
Help meee!! PLZZZZ It's worth 20 points and if you get it right I will mark brainlist.
professor190 [17]

Answer: I Think it should be Mixture.

Explanation: Because titanium is a mixture and its only 1% of the 2nd option and its not a pure substance and it might be a compound.

4 0
3 years ago
At its widest point, the diameter of a bottlenose dolphin is 0.50 m. Bottlenose dolphins are particularly sleek, having a drag c
fiasKO [112]

Answer:

497.00977 N

3742514.97005

Explanation:

\rho = Density of water = 1000 kg/m³

C = Drag coefficient = 0.09

v = Velocity of dolphin = 7.5 m/s

r = Radius of bottlenose dolphin = 0.5/2 = 0.25 m

A = Area

Drag force

F_d=\frac{1}{2}\rho CAv^2\\\Rightarrow F_d=\frac{1}{2}\times 1000 \times 0.09(\pi 0.25^2)7.5^2\\\Rightarrow F_d=497.00977\ N

The drag force on the dolphin's nose is 497.00977 N

at 20°C

\mu = Dynamic viscosity = 1.002\times 10^{-3}\ Pas

Reynold's Number

Re=\frac{\rho vd}{\mu}\\\Rightarrow Re=\frac{1000\times 7.5\times 0.5}{1.002\times 10^{-3}}\\\Rightarrow Re=3742514.97005

The Reynolds number is 3742514.97005

8 0
3 years ago
Other questions:
  • calculate the energy spent on spraying a drop of mercury of 1 cm radius into 10^6 droplets all of same radius. surface tension o
    7·1 answer
  • Approximately what percentage of Earth’s radius is represented by the crust?
    7·1 answer
  • A boy is inning with a kinetic energy of 810j. If the boy has a mass of 80kg. What is his speed ?
    5·1 answer
  • A person is pulled to the right on a sled (total mass of 52.9 kg) across the surface of a frozen pond with a force of 67.7 Newto
    9·1 answer
  • UPVOTE FOR EVERY ANSWER!
    11·1 answer
  • Identify the magnetic north pole of Earth’s magnet?
    6·2 answers
  • Please I need help ill give u 50 points
    14·1 answer
  • Which task would be impossible without radio waves ?
    13·2 answers
  • Investigating arson can be a very complicated and complex job, as you learned in the unit! It is also generally a time sensitive
    15·1 answer
  • Amal uses a pulley to lift a concrete block. She applies a force of of 95N. The force exerted on the concrete block is 95N. What
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!