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
vfiekz [6]
3 years ago
14

A thermometer is removed from a room where the temperature is 70° F and is taken outside, where the air temperature is 10° F. Af

ter one-half minute the thermometer reads 60° F. What is the reading of the thermometer at t = 1 min? (Round your answer to two decimal places.) ° F How long will it take for the thermometer to reach 30° F? (Round your answer to two decimal places.)
Physics
1 answer:
vekshin13 years ago
8 0

Answer:

T=51.64^\circ F

t=180.10s

Explanation:

The Newton's law in this case is:

T(t)=T_m+Ce^{kt}

Here, T_m is the air temperture, C and k are constants.

We have

70^\circ F in t=0

So:

T(0)=70^\circ F\\T(0)=10^\circ F+Ce^{k(0)}\\70^\circ F=10^\circ F+C\\C=70^\circ F-10^\circ F=60^\circ F

And we have 60^\circ F in t=30 s, So:

T(30)=60^\circ F\\T(30)=10^\circ F+(60^\circ F)e^{k(30)}\\60^\circ F=10^\circ F+(60^\circ F)e^{k(30)}\\50^\circ F=(60^\circ F)e^{k(30)}\\e^{k(30)}=\frac{50^\circ F}{60^\circ F}\\(30)k=ln(\frac{50}{60})\\k=\frac{ln(\frac{50}{60})}{30}=-0.0061

Now, we have:

T=10^\circ F+(60^\circ F)e^{-0.0061t}(1)

Applying (1) for t=1 min=60s:

T=10^\circ F+(60^\circ F)e^{-0.0061*60}\\T=10^\circ F+(60^\circ F)0.694\\T=10^\circ F+41.64^\circ F\\T=51.64^\circ F

Applying (1) for T=30^\circ F:

30^\circ F=10^\circ F+(60^\circ F)e^{-0.0061t}\\30^\circ F-10^\circ F=(60^\circ F)e^{-0.0061t}\\-0.0061t=ln(\frac{20}{60})\\t=\frac{ln(\frac{20}{60})}{-0.0061}=180.10s

You might be interested in
A research vessel is mapping the bottom of the ocean using sonar. It emits a short sound pulse called "ping" downward. The frequ
Svetradugi [14.3K]

Answer:

d = 4180.3m

wavelengt of sound is 0.251m

Explanation:

Given that

frequency of the sound is 5920 Hz

v=1485m/s

t=5.63s

let d represent distance from the vessel to the ocean bottom.

an echo travels a distance equivalent to 2d, that is to and fro after it reflects from the obstacle.

velocity=\frac{distance}{time}\\\\ v=\frac{2d}{t} \\\\vt=2d\\\\d=\frac{vt}{2}

d=\frac{1485*5.63}{2}\\d= 4180.3m

wavelengt of sound is \lambda = v/f

= (1485)/(5920)

= 0.251 m

7 0
3 years ago
Which of the following would produce the most power?
Fantom [35]

Answer:

A mass of 10 kilograms lifted 10 meters in 5 seconds.

Explanation:

Power can be defined as the energy required to do work per unit time.

Mathematically, it is given by the formula;

Power = \frac {Energy}{time}

But Energy = mgh

Substituting into the equation, we have

Power = \frac {mgh}{time}

Given the following data;

Mass = 10kg

Height = 10m

Time = 5 seconds

We know that acceleration due to gravity is equal to 9.8 m/s²

Power = \frac {10*9.8*10}{5} = 490 Watts

Hence, a mass of 10 kilograms lifted 10 meters in 5 seconds would produce the most power.

6 0
2 years ago
A particle, of mass 6 kg, is in equilibrium on a rough horizontal plane under a force o-f magnitude T N, which acts at an angle
Helga [31]

Answer:

T is less than or equal to 19 N

Explanation:

3 0
3 years ago
Will give correct answer brainliest<br><br>5 kg m/s<br>8kg m/s<br>80 kg m/s<br>200 kg m/s​
o-na [289]

Answer: Here this will help you..

Explanation:

1 kg-m/s to kilogram-force meter/second = 1 kilogram-force meter/second

5 kg-m/s to kilogram-force meter/second = 5 kilogram-force meter/second

10 kg-m/s to kilogram-force meter/second = 10 kilogram-force meter/second

20 kg-m/s to kilogram-force meter/second = 20 kilogram-force meter/second

30 kg-m/s to kilogram-force meter/second = 30 kilogram-force meter/second

40 kg-m/s to kilogram-force meter/second = 40 kilogram-force meter/second

50 kg-m/s to kilogram-force meter/second = 50 kilogram-force meter/second

75 kg-m/s to kilogram-force meter/second = 75 kilogram-force meter/second

100 kg-m/s to kilogram-force meter/second = 100 kilogram-force meter/second

8 0
2 years ago
Show your working please ​
saw5 [17]

Explanation:

There's not enough information in the problem to solve it.  We need to know either the initial speed of the lorry, or the time it takes to stop.

For example, if we assume the initial speed of the lorry is 25 m/s, then we can find the rate of deceleration:

v² = v₀² + 2aΔx

(0 m/s)² = (25 m/s)² + 2a (50 m)

a = -6.25 m/s²

We can then use Newton's second law to find the force:

F = ma

F = (7520 kg) (-6.25 m/s²)

F = -47000 N

3 0
3 years ago
Other questions:
  • The emf induced in a coil that is rotating in a magnetic field will be at a maximum at which moment?
    9·1 answer
  • A dog sees a cat and runs for 10 s at 4.8 m/s before the cat runs up a tree
    9·1 answer
  • Which phrase most closely characterizes a person's sense of self?
    7·1 answer
  • Diana would like to observe the movements of a paramecium. Which of the following tools would be best for Diana to use? A. hand
    6·2 answers
  • The speed of an object and direction of its travel is?
    10·1 answer
  • 5. What structure did Friedrich Kekule discover that allowed carbon atoms can bond
    12·1 answer
  • Priya is responsible for collecting canned food along three different streets for her school's annual Thanksgiving Food Drive. S
    14·1 answer
  • Please answer fast ————-
    15·1 answer
  • T or F: In situations of inhalation poisoning, you should call for help before you attempt a rescue.
    6·1 answer
  • If the applied force is 60 N and the lower mass is 1.0 kg, what is the tension in the string?(frictionless surface)
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!