Can work done=mass*acceleration*displacement(work=m*a*s)

Find the resistance at 50°c of copper wire 2mm in diameter and 3m long

mr Goodwill [35]

0.0179 ohms for copper.

0.0184 ohms for annealed copper

Ď = R (A/l) where

Ď = electrical resistivity

R = electrical resistance of a uniform specimen

A = cross sectional area

l = length

Solve for R by multiplying both sides by l/A

R = Ď(l/A)

The cross section of the wire is pi * 1^2 mm = 3.14159 square mm = 3.14159e-6 square meters.

The length is 3 meters. So l/A = 3/3.14159e-6 = 9.5493e5

Ď for copper is 1.68e-8 so 1.68e-8 * 9.5493e5 = 1.60e-2 ohms at 20 C

But copper has a temperature coefficient (Î±) of 0.00386 per degree C.

So the resistance value needs to be adjusted based upon how far from 20 C the temperature is.

50 - 20 = 30 C

So 0.00386 * 30 = 0.1158 meaning that the actual resistance at 50 C will be 11.58% higher.

So 1.1158 * 0.016 = 0.0179 ohms.

If you're using annealed copper, the values for Ď and the temperature coefficient change.

Ď = 1.72e-8

Î± = 0.00393

Doing the math, you get

1.72e-8 * 9.5493e5 * (1 + 30 * 0.00393) = 0.0184 ohms

8 0

3 years ago

A ball is thrown vertically down from the edge of a cliff with a speed of 4 m/s, how high is the cliff, if it took 12 s for the

Vesna [10]

Answer:

The height of the cliff from which the ball was dropped from is 224.4m.

\overline{v}={\frac{\Delta x}{\Delta t}}

Given the data in the question;

Initial velocity of the ball;

Time taken by the ball to reach the ground;

Distance or Height of the cliff from which the ball was thrown from;

To get the height of the Cliff, we use the Second Equation of Motion:

Where s is the distance or height, is the initial velocity, t is the time and a is the acceleration. Since the ball was thrown down from a certain height (cliff), its is now under the influence of gravity. acceleration due to gravity;

Hence, the equation becomes

We substitute the given values into the equation

Therefore, the height of the cliff from which the ball was dropped from is 224.4m

Explanation:

3 0

3 years ago

Read 2 more answers

Alice kicks a 0.25 kg soccer ball with 0.5 N of force. What force does the ball exert on Alice’s foot as she kicks it

Lelechka [254]

You do not doubt it. The third Law of Newton really works. I would say it is the most reliable law of the Universe. Action and reaction. It is not subject to special conditions, it works always. If an object exerts a force over other object, the second object exerts a force of equal magnitude but in the opposed direction over the first.

So, the answer, undoubtedly, is that the ball exerts a force of 0.5 N over Alices's foot as she kicks it.

7 0

4 years ago

Read 2 more answers

My dad gifted me a calculator. I have observed that very small cells are used in a calculator. What are these cells called and w

Morgarella [4.7K]

The cells are called insibatss, I think I spelled that right but

7 0

3 years ago

If you drop a bouncing ball from a height of 40 centimeters, explain why it can only bounce back up to a height of less than 40

iren2701 [21]

Answer:

Due to energy loss while collision ball will not reach to same height while if there is no energy loss then in that case ball will reach to same height

Explanation:

As we know that initially ball is held at height h = 40 cm

So here we can say that kinetic energy of the ball is zero and potential energy is given as

$U = mgH$

now when strike with the ground then its its fraction of kinetic energy is lost in form of other energies

So the ball will left rebound with smaller energy and hence it will reach to height less than the initial height

While if we assume that there is no energy loss during collision then in that case ball will reach to same height again

8 0

3 years ago