Why it is advise to clean the ends of connecting wires before connecting them?

Physics

2 answers:

densk [106]3 years ago

8 0

To avoid poor contact and consequently the increase of the electrical resistance at the junction.

Svetradugi [14.3K]3 years ago

5 0

If dirt and grease were good conductors of electrical current, then we could make wire
out of dirt and grease instead of expensive copper. Sadly, they're not. So a coating of
dirt and grease on the wire can have a substantial impact on the connection, and can
even block the flow of current across the connection completely. Moreover, in the case
where the ends of the wires are to be soldered, solder does not adhere to dirty wire.

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The ideal mechanical advantage of an inclined plane is 3.5, and its efficiency is 0.6. What is the mechanical advantage of the i

Nadya [2.5K]

Mechanical advantage = ideal mechanical advantage x efficiency = 3.5 x 0.6 = 2.1
The mechanical advantage of the inclined plane is 2.1

7 0

3 years ago

A rope is tied to a box and used to pull the box 2.3 m along a horizontal floor. The rope makes an angle of 30∘ with the horizon

Savatey [412]

Answer:

Answered

Explanation:

A) The work done by gravity is zero because displacement and the gravitational force are perpendicular to each other.

W= FS cosθ

θ= 90 ⇒cos90 = 0 ⇒W= 0

B) work done by tension

W= Tcosθ×S= 5cos30×2.30= 10J

C) Work done by friction force

W= f×s=1×2.30= 2.30 J

D) Work done by normal force is Zero because the displacement and the normal force are perpendicular to each other.

E) The net work done= Work done by tension in the rope - frictional work

=10-2.30= 7.7 J

6 0

3 years ago

Use this formula to solve this problem:

Maslowich

Well, you gave us the formula to calculate power from work and time,
but you didn't give us the formula for work. We have to know that.

   Work = (force) x (distance)

The work to raise Sara to the top of the hill is

   Work = (300 N) x (15 meters)

   = 4,500 newton-meters = 4,500 joules .

Now we're ready to use the formula that you gave us. (Thank you.)

Power = (work) / (time)

= (4,500 joules) / (10 seconds)

450 joules/second = 450 watts.

6 0

3 years ago

Read 2 more answers

A 1300 kg car starts at rest and rolls down a hill from a height of 10.0 m. It then moves across a

Makovka662 [10]

Answer:

0.51 m

Explanation:

Using the principle of conservation of energy, change in potential energy equals to the change in kinetic energy of the spring.

Kinetic energy, KE=½kx²

Where k is spring constant and x is the compression of spring

Potential energy, PE=mgh