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
I am Lyosha [343]
3 years ago
12

You are given a copper bar of dimensions 3 cm × 5 cm × 8 cm and asked to attach leads to it in order to make a resistor. (a) If

you want to achieve the SMALLEST possible resistance, you should attach the leads to the opposite faces that measure A) 3 cm × 5 cm. B) 3 cm × 8 cm. C) 5 cm × 8 cm. D) Any pair of faces produces the same resistance. (b) If you want to achieve the LARGEST possible resistance, you should attach the leads to the opposite faces that measure A) 3 cm × 5 cm. B) 3 cm × 8 cm. C) 5 cm × 8 cm. D) Any pair of faces produces the same resistance.
Physics
1 answer:
dem82 [27]3 years ago
4 0

Answer:

A) If you want to achieve the SMALLEST possible resistance, you should attach the leads to the opposite faces that measure b) 5 cm by 8 cm.

B) If you want to achieve the LARGEST possible resistance, you should attach the leads to the opposite faces that measure a) 3 cm × 5 cm

Explanation:

Resistivity is directly proportional to lenght and inversely properly to cross sectional area.

For the first case, 5 cm by 8 cm gives the largest area and leave 3 cm as the lenght. The resistivity of the metal will be smallest in these dimensions.

For the second case, 3 cm by 5 cm gives the smallest area, leaving 8 cm as the lenght. This is the maximum arrangement that can give the largest resistance possible.

You might be interested in
find the time taken, if the speed of a train increased from 72 km/hr to 90 km/hr for 234 km. leave your answer in seconds
Airida [17]

Answer:

Time taken = 10400 s

Explanation:

Given:

Initial speed of the train, u=72\textrm{ km/h}=72\times \frac{5}{18}=20\textrm{ m/s}

Final speed of the train, v=90\textrm{ km/h}=90\times \frac{5}{18}=25\textrm{ m/s}

Displacement of the train, S=234\textrm{ km}=234\times 1000=234000\textrm{ m}

Using Newton's equation of motion,

v - u = at\\a=\frac{v-u}{t}

Now, using Newton's equation of motion for displacement,

v^{2}-u^{2}=2aS

Now, plug in the value of a=\frac{v-u}{t} in the above equation. This gives,

v^{2}-u^{2}=2\times \frac{v-u}{t}\times S\\(v+u)(v-u)=\frac{2(v-u)S}{t}\\t=\frac{2(v-u)S}{(v+u)(v-u)}\\t=\frac{2S}{v+u}

Now, plug in 234000 m for S, 25 m/s for v and 20 m/s for u. Solve for t.

t=\frac{2S}{v+u}\\t=\frac{2\times 234000}{25+20}\\t=\frac{468000}{45}=10400\textrm{ s}

Therefore, the time taken by the train is 10400 s.

3 0
3 years ago
You do 45.0 joules of work and 3.00 seconds how much power do you use​
Arada [10]

Answer:

15 watt

Explanation:

Power is the rate at which work is done.

This means you divide the work done with the amount of time used to perform the work.

The formula for Power is : P = W/t  where;

W= work done in J = 45

t= time in seconds = 3 sec

P= 45/ 3 = 15 watt

8 0
3 years ago
What is the mechanical advantage of a pulley system​
tatuchka [14]

Answer:

Pulleys accomplish 2 separate operations throughout the computer controlled additional benefit technologies listed elsewhere here.

Explanation:

  • If indeed the pulley would be connected to that same attachment point, these are named a corrected pendulum or perhaps a change in direction. Its job should be to reverse the trajectory of that same rope pull.  
  • Unless the pulley would be connected to that same load, this same pulley seems to be a detachable as well as a mechanical additional benefit.
7 0
2 years ago
Describe the motion of an object that has an acceleration of 0 mi./s squared
miskamm [114]
The object does not move.
5 0
3 years ago
We can see Objects because of
Amiraneli [1.4K]

Answer:

I believe it's A.)

Explanation:

Although light comes into our atmosphere through refraction, it reaches our eyes only through reflection from objects. So when light rays reflect off an object and enter the eyes through the cornea you can then see that object.

Hope this helps you out : )

7 0
3 years ago
Other questions:
  • How long would it take Exena to close the door if she doubled the magnitude of the force applied to the door
    15·1 answer
  • Given equation is F=mv ×v/R<br> what is the relationship exist between F and R?
    11·1 answer
  • WHAT TYPE OF MOON IS THIS WILL MARK AS BRAINLIEST :)
    12·2 answers
  • For a stationary observer, when the source of a sound is moving, its pitch appears to change.
    7·2 answers
  • An AC voltage, whose peak value is 17.0 V, is across a 329.0 Ohm resistor. What is the value of the rms current in the resistor?
    10·1 answer
  • Select all that apply.
    10·2 answers
  • Which is not a characteristic of a compound? Different samples have different properties Can be represented by a chemical formul
    10·1 answer
  • ميل الجسم الى مقاومة التغير في حالته الساكنه أو الحركية يسمى ؟
    15·2 answers
  • The girl in the diagram is accelerating down the hill, What is the girl’s acceleration.
    6·2 answers
  • A Carnot engine performs 2.5 * 104 J of work in each cycle and has an efficiency of 66%. (a) How much heat does the engine extra
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!