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2 years ago

In which of the following conditions would there be the most resistance?

Physics

1 answer:

Natasha2012 [34]2 years ago

8 0

Answer:

A) A warm wire

Explanation:

A warm wire has the most resistance. Heating the metal wire causes atoms to vibrate more, which in turn makes it more difficult for the electrons to flow, increasing resistance. Heating the wire increases resistivity.

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A child has two red wagons, with the rear one tied to the front by a (non-stretching) rope. If the child pushes on the rear wago

Sergeeva-Olga [200]

Answer:

The rear wagon gains the kinetic energy, but the front wagon will remain at rest.

The two-wagon system will gain a kinetic energy $\dfrac{1}{16}$ of the kinetic energy gained by the rear wagon.

Explanation:

Let's consider that the masses of the wagons to be 'M'. When the child pushes the rear wagon let's assume that the velocity of the rear wagon be 'v'.

Therefor the kinetic energy gained by the rear wagon be $K_{r} = \frac{1}{2}Mv^{2}$ .

Now let's assume that the velocity of the centre of mass (C), as shown in the figure, be 'V'. So from momentum conservation law we can write,

$&& Mv = (M + M)V\\\\&or,& V = \frac{v}{2}$

Now the centre of mass ( $M_{C}$ ) is given by

$M_{C} = \frac{M \times M}{M + M} = \frac{M}{2}$

So the kinetic energy ( $K_{C}$ ) of the system will be

$K_{C} = \frac{1}{2}M_{C}V^{2} = \frac{1}{2}\frac{M}{2}(\frac{v}{2})^{2} = \frac{1}{16}Mv^{2}$

5 0

2 years ago

Động cơ khởi động của một ô tô bị quay chậm , thợ cơ khí quyết định phải thay động cơ , dây cap hoặc acquy. Hướng dẫn sử dụng nó

tester [92]

Answer:

Việc nắm được các thông số của bình ắc quy cho xe máy sẽ giúp bạn ... Khi di chuyển với tốc độ chậm hoặc gặp phải tắc đường, đối với xe có ... sau: ắc quy có điện áp 12V, CCA = 600, có nghĩa là ắc quy có thể cung cấp

Explanation:

8 0

2 years ago

2. True or false. As a wave travels through a given material its velocity changes.

laila [671]

Answer:

ture

Explanation:

6 0

3 years ago

There is a known potential difference between two charged plates of 12000 Volts. An object with a charge of 6.5 x 10-6 C charge

s344n2d4d5 [400]

Answer:

1.97 m/s.

Explanation:

From the question,

Using the law of conservation of energy,

The energy stored in the charged plate = Kinetic energy of the mass

1/2(qV) = 1/2mv².......................... Equation 1

Where q = charge, V = voltage, m = mass, v = velocity.

make v the subject of the equation

v = √(qV/m)......................... Equation 2

Given: q = 6.5×10⁻⁶ C, V = 12000 Volts, m = 0.02 kg

Substitute these values into equation 2

v = √(6.5×10⁻⁶×12000 /0.02)

v = √3.9

v = 1.97 m/s.

7 0

3 years ago

Which of the following is least likely to result from seafloor spreading

Assoli18 [71]

Answer:

An reversal in the magnetic fields of the north and south pole. This would be the most logical option for me...correct me if I'm wrong.

Explanation:

New seafloor is formed when magma is forced upward toward the surface at a mid-ocean.

7 0

2 years ago