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4 years ago

Assuming that voltage remains constant, what happens to the current in a filament if it is replaced by a longer wire?

Physics

2 answers:

ruslelena [56]4 years ago

8 0

Answer:

the current decreases

Explanation:

Elena L [17]4 years ago

4 0

Answer:

Choice B: The current decreases.

Explanation:

The resistance of a conductor is proportional to its length when radius and resistivity stays the same. The resistance of the longer filament will be greater than the resistance of the initial one.

For Ohmic conductors,

$\displaystyle I = \frac{V}{R}$ ,

where

$I$ is the current through the conductor,
$V$ is the voltage across the conductor, and
$R$ is the resistance of the conductor.

Voltage here stays the same. Increasing the resistance $R$ of the conductor will reduce the current.

The filament might heat up over time. The filament might not be an ohmic conductor. Still, a similar trend shall exist. Resistance will be greater in the longer filament, and current will decrease.

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A bullet of mass 0.107 kg traveling horizontally at a speed of 300 m/s embeds itself in a block of mass 3 kg that is sitting at

melisa1 [442]

Answer:

165.77J

Explanation:

M₁ = 0.107kg

u₁ = 300m/s

m₂ = 3kg

u₂ = 0

v =

m₁u₁ + m₂u₂ = (m₁ + m₂)V

(0.107*300) + 0 = (0.107 + 3)V

V = 32.1 / 3.107 = 10.33m/s

kinetic energy of the system after collision =

½m1v² + ½m2v²

K.E = ½(m1 + m2)v²

K.E = ½(0.107+3) * 10.33²

K.E = 165.77J

5 0

3 years ago

A circular saw spins at 6000 rpm , and its electronic brake is supposed to stop it in less than 2 s. As a quality-control specia

Alona [7]

Answer:

a. yes

Explanation:

The initial speed of the circular saw is:

$\dot n_{o} = \frac{6000}{60} \,\frac{rev}{s}$

$\dot n_{o} = 100\,\frac{rev}{s}$

Deceleration rate needed to stop the circular saw is:

$\ddot n = -\frac{100\,\frac{rev}{s} }{2\,s}$

$\ddot n = - 50\,\frac{rev}{s^{2}}$

The number of turns associated with such deceleration rate is:

$\Delta n = \frac{\dot n^{2}}{2\cdot \ddot n}$

$\Delta n = \frac{\left(100\,\frac{rev}{s} \right)^{2}}{2\cdot \left(50\,\frac{rev}{s^{2}} \right)}$

$\Delta n = 100\,rev$

Since the measured number of revolutions is lesser than calculated number of revolution, the circular saw meets specifications.

8 0

3 years ago

Which of the following types of energy is potential energy A. gravitational energy

katovenus [111]

There are many forms of energy, but they can all be put into two categories: kinetic and potential. Kinetic energy is motion––of waves, electrons, atoms, molecules, substances, and objects. Potential energy is stored energy and the energy of position––gravitational energy

4 0

3 years ago

. Two parallel conducting plates are separated by 10.0 cm, and one of them is taken to be at zero volts. (a) What is the electri

exis [7]

Answer:

Explanation:

electrical field strength = potential diff / distance

= ( 450 - 0 ) / 8 x 10⁻²

= 5625 V/m

b )

potential difference = electric field x distance

= 5625 x .10

= 562.5 V

6 0

3 years ago

A 600g boulder has a density of 8 g/cm3. What is the volume of the boulder

Amiraneli [1.4K]

Density can be calculated using the following rule:
density = mass / volume

Since the density is given as 8 gm/cm^3 and the mass is given as 600 grams, therefore, all we need to do is substitute in the equation to get the value of the volume as follows:
8 = 600 / volume
volume = 600 / 8 = 75 cm^3

3 0

4 years ago