To solve this problem we will apply the concepts related to resistance as a function of temperature, product of the relationship between the squared voltage and the power. Mathematically this is,

$R = \frac{v^2}{P}$

Here,

R = Resistance (At function of temperature)

v = Voltage

P = Power

Then we have,

R at 140°C (7 times room temperature),

$R(140\°C) = \frac{125^2}{7.5}$

$R(140\°C) = 2083.33\Omega$

The relationship between normal temperature and increased temperature would then be given by,

$R(140\°C) = R(20\°C)(1 +\alpha (\Delta T))$

$R(140\°C) = R(20\°C)(1+(4.5*10^{-3})(140-20))$

$R(20\°C) = \frac{2083.33}{1.54}$

$R(20\°C) = 1352.81\Omega$

Therefore the correct value of the group of answer is 1350

5 0

3 years ago

When a burning stick of increase is moved fast in a circle a circle of red light is seen.

anzhelika [568]

Answer:

The impression of the image on the retina lasts for about 1/16th of a second after the removal of the object. If a burning stick of incense is revolved at a rate of more than sixteen revolutions per second, we see a circle of red light due to persistence of vision.

Explanation:

7 0

3 years ago

A hovering mosquito is hit by a raindrop that is 50 times as massive and falling at 8.4 m/s, a typical raindrop speed. How fast

kenny6666 [7]

The final velocity after the collision is 8.2 m/s

Explanation:

We can solve this problem by using the law of conservation of momentum: in fact, if we consider the system to be isolated (=no external unbalanced forces), the total momentum of the raindrop+mosquito must be conserved before and after the collision.

If the collision is perfectly inelastic, moreover, the raindrop and the mosquito stick together and travel at the same velocity v after the collision.

Mathematically:

$p_i = p_f\\m_1 u_1 + m_2 u_2 = (m_1+m_2)v$

where:

$m_1$ is the mass of the first mosquito

$u_1 = 0$ is the initial velocity of the mosquito

$m_2 = 50 m_1$ is the mass of the raindrop

$u_2 = 8.4 m/s$ is the initial velocity of the raindrop

$v$ is the final combined velocity of the raindrop+mosquito

Re-arranging the equation and substituting, we find:

$m_1 u_1 + 50 m_1 u_2 = (m_1 + 50 m_1) v\\50 m_1 u_2 = 51 m_1 v\\50 u_2 = 51 v\\v=\frac{50}{51}u_2 = \frac{50}{51}(8.4)=8.2 m/s$

Learn more about momentum here:

brainly.com/question/7973509

brainly.com/question/6573742

brainly.com/question/2370982

brainly.com/question/9484203

#LearnwithBrainly

4 0

4 years ago

How do you know that light travels faster than

Dahasolnce [82]

Answer:

Explanation:

Answer

How about a thunder storm. I don't know if you live in a city or out in the sticks as I do. Lighting is very obvious and it is not a good idea to be out when experiencing a thunderstorm, especially in an open field. You might be the only thing around that will cause the lightning to be connected to the ground.# Seconds later, you will hear the thunder which is quite harmless. If you live in the city, observing this is not quite so easy. There are all kinds of buildings around and some of them may block your view.

#The great golfer, Lee Travino, was "hit" by lightening storm twice while playing in tournaments.

8 0

2 years ago