All categories

3 years ago

In which situation will the lowest resistance occur?

Physics

2 answers:

insens350 [35]3 years ago

8 0

Answer:

thick wire and cold temperatures

Lena [83]3 years ago

6 0

Answer: There may be two types of resistances here:

Air resistance: for example when something is falling down, the air will push the object upwards. As a bigger surface has the object, more air is pushing, so if you want to reduce the resistance yo must reduce the surface area. For example, a sheet of paper will experience more resistance if it is open if you make a small ball with it.

Electric resistance: This is the resistance of conductors against the electrons that try to travel along with it.

there are two equations here.

R = p*L/A, this talks about the volume and density of the conductor, where p is the density, L is the length and A is the area perpendicular to the direction in which the electricity flows.

Then if you reduce the length, and increase the area, the resistance will be reduced.

the other equation is: R(T) = R0( 1 + a*(T - 20°))

Where R0 is the resistance at 20° and a is a coefficient for T = 20°.

Here, you can see that at smaller temperatures, the resistance decreases, so we can conclude that we must increase the area, and decrease the length and temperature.

You might be interested in

Two particles, each of mass m, are initially at rest very far apart.Obtain an expression for their relative speed of approach at

PSYCHO15rus [73]

Answer:

$|\Delta v |=\sqrt{\frac{4Gm}{d} }$

Explanation:

Consider two particles are initially at rest.

Therefore,

the kinetic energy of the particles is zero.

That initial K.E. = 0

The relative velocity with which both the particles are approaching each other is Δv and their reduced masses are

$\mu= \frac{m_1m_2}{m_1+m_2}$

now, since both the masses have mass m

therefore,

$\mu= \frac{m^2}{2m}$

= m/2

The final K.E. of the particles is

$KE_{final}=\frac{1}{2}\times \mu\times \Delta v^2$

Distance between two particles is d and the gravitational potential energy between them is given by

$PE_{Gravitational}= \frac{Gmm}{d}$

By law of conservation of energy we have

$KE_{initial}+KE_{final}= PE_{gravitaional}$

Now plugging the values we get

$0+\frac{1}{2}\frac{m}{2}\Delta v^2= -\frac{Gmm}{d}$

$|\Delta v |=\sqrt{\frac{4Gm}{d} }$

$=\sqrt{\frac{Gm}{d} }$

This the required relation between G,m and d

5 0

2 years ago

Two identical charges q placed 2.0 mapart exert forces of magnitude 4.0 N on each other What is the value of the charge q? a) q

katen-ka-za [31]

Answer:

c) $4.2*10^{-5}C$

Explanation:

Coulomb's law says that the force exerted between two charges is inversely proportional to the square of distance between them, and is given by the expression:

$F=\frac{kq_{1}q_{2}}{r^{2}}$

where k is a proportionality constant with the value $k=9*10^{9}\frac{Nm^{2}}{C^{2}}$

In this case $q_{1}=q_{2}=q$ , so we have:

$F=\frac{kq^{2}}{r^{2}}$

Solving the equation for q, we have:

$kq^{2}=Fr^{2}$

$q^{2}=\frac{Fr^{2}}{k}$

$q=\sqrt{\frac{Fr^{2}}{k}}$

Replacing the given values:

$q=\sqrt{\frac{4.0N*(2.0m)^{2}}{9*10^{-9}\frac{Nm^{2}}{C^{2}}}}$

$q=4.2*10^{-5}C$

3 0

3 years ago

You kick a soccer ball of mass 0.41 kg. the ball leaves your foot with an initial speed of 23 m/s. (a what is the magnitude of t

svetoff [14.1K]

Impulse describes the change of momentum. Since we don't know the momentum of the soccer ball before the hit, this question is hard to answer. If you assume the momentum of the ball before the hit was p = 0, then the change in momentum is just Δp = Impulse = mv.

7 0

3 years ago

Read 2 more answers

2 questions, brainliest if correct. please only answer if you really know!

Iteru [2.4K]

Answer:

<h2>1. Friction is A. a force</h2>

<h2>2. An unbalanced force is B. When the object moves and accelerates</h2>

3 0

2 years ago

Read 2 more answers

Consider the following list of numbers. 129, 685, 125, 511, 601, 52, 46 The height of a binary search tree is the maximum number

NemiM [27]

Answer:

The height of the tree is three (3) deep

Explanation:

It's 3 deep

Under 129, comes 125 and 685;

Under 125, comes 52 : Under 685, comes 511;

Under 52, comes 46 : Under 511, is 601.

This is illustrated below.

129

∧

125,685

|,|

52,511

|,|

46,601

5 0

3 years ago