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3 years ago

Will increasing length and cross-sectional area increase the resistance of an object?

Physics

1 answer:

Klio2033 [76]3 years ago

5 0

Answer:

Increasing length increases resistance

increasing cross sectional area reduces the resistance

Explanation:

The formula for resistance of an object is

$r = d \frac{l}{a}$

where r is resistance, d is resistivity of the material, l is length of material and a is cross sectional area of the object. This equation shows us that resistance is directly proportional to length and inversely proportional to cross sectional area. Hence, increasing length increases resistance while increasing cross sectional area reduces the resistance.

If these 2 variables are varied to the same extent, the net effect can be zero on the resistance.

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The power output of a tuba is 0.35 W. At what distance is the sound

STALIN [3.7K]

The distance of the sound from the tuba is 4.82 m.

The area of the tuba is calculated as follows;

I = P/A

where;

I is intensity of sound
P is power
A is area

A = P/I

A = 0.35 / (1.2 x 10⁻³)

A = 291.67 m²

<h3>Distance of the sound</h3>

Area = 4πr²

$r = \sqrt{\frac{A}{4\pi} } \\\\r = \sqrt{\frac{291.67}{4\pi} } \\\\r = 4.82 \ m$

Thus, the distance of the sound from the tuba is 4.82 m.

Learn more about intensity of sound here: brainly.com/question/4431819

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3 years ago

Explain briefly where the energy come from when a liquid Rises against Gravity in a capillary tube

SSSSS [86.1K]

Answer:

Surface tension

Explanation:

When liquid rises against gravity in a capillary tube, the energy comes from surface tension.

This is because surface tension is the energy that's needed to increase the liquid surface area.

As a result of hydrogen bonding present in Water, it usually has high surface tension which makes it to possess a tough skin that can make it not to break despite high forces applied to it.

The liquid will be in contact with the capillary tube and as such experiences surface tension which in turn makes the capillary tube to experience an upward force that makes the liquid begin to rise up.

The more the liquid keeps rising, the more it gets to the point where the surface tension becomes balanced from the weight of the liquid.

3 0

3 years ago

What is true about energy that is added to a closed system

arsen [322]

It does work or increases thermal energy

4 0

4 years ago

Read 2 more answers

Sitting in a second-story apartment, a physicist notices a ball moving straight upward just outside her window. The ball is visi

gregori [183]

Answer:

1.013 s

Explanation:

You can solve this problem using the equations for constant acceleration motion. The velocity at the bottom of the window can be found using this expression:

$(x-x_o) = \frac{1}{2} at^2 + v_ot = -\frac{1}{2}gt^2 + v_ot$

the gravity is negative as it opposes the movement.

$(x-x_o) = -\frac{1}{2}gt^2 + v_ot\\v_o = \frac{(x-x_o)+\frac{1}{2}gt^2}{t} = \frac{1.19m+\frac{1}{2} 9.81m/s^2(0.2s)^2}{0.2s} = 6.931 m/s$

Now, the time elapsed before the ball reappears is 2 times the time that it takes for the ball to go from the bottom of the window, reach maximum height, and reach again the bottom of the window, minus 2 times the time that it takes for the ball to travel from the top to the bottom of the window. The time that takes to the ball to reach maximum height, or in other words, to time that takes for the velocity of the ball to go from vo to 0m/s:

$t_1 = \frac{0m/s - v_o}{g} = \frac{-6.931 m/s}{-9.81m/s^2} = 0.706 s$

Then:

$t = 2t_1 - 2*0.2s = 2*(0.706s) - 0.4s = 1.013 s$

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3 years ago

A ball is tossed up into the air, reaches its highest point and returns to its original position. which of the following is true

Gekata [30.6K]

Answer: (Projectile motion)

Option A — At its highest point the ball’s velocity is 0 and so it it’s acceleration (0).

This is because at the highest point, the ball’s direction changes. This is due to the forces counteracting the upward momentum (mass*velocity) of the ball, so the ball slows down and when it reaches it highest point starts to change direction and fall back down. In the short period of time at which its at its highest point, it’s velocity reaches 0 for a very short amount of time, and so does its acceleration.

3 0

3 years ago