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Nutka1998 [239]

2 years ago

10

Three wires are made of copper having circular cross sections. Wire 1 has a length l and radius r. Wire 2 has a length l and rad

ius 2r. Wire 3 has a length 2l and radius 3r. Which wire has the smallest resistance?

1 answer:

Alex73 [517]2 years ago

4 0

Explanation:

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Calculate the change in internal energy (δe) for a system that is giving off 25.0 kj of heat and is changing from 12.00 l to 6.0

lora16 [44]

Since the system itself is giving off heat, this is a reduction in the internal energy.

heat = - 25,000 J

Since work is being done on the system, therefore it is an additional energy to the system. Work is given as:

work = - P dV

work = - 1.50 atm (6 L – 12 L)

work = 9 L atm

Since it is given that 1 L atm is equivalent to 101.3 J, therefore the total energy added is:

energy due to work = 9 L atm (101.3 J / 1 L atm)

energy due to work = 911.7 J

Therefore the total change in internal energy is the sum of heat and energy due to work:

Change in internal energy = - 25,000 J + 911.7 J

Change in internal energy = - 24,088.3 J

<span>Therefore, approximately 24.1 kJ of energy is lost by the system in the total process.</span>

<span>
</span>

<span>Answer:</span>

<span>-24.1 kJ</span>

8 0

2 years ago

Read 2 more answers

You've always wondered about the acceleration of the elevators in the 101 story-tall Empire State Building. One day, while visit

love history [14]

To develop this problem we will proceed to convert all units previously given to the international system for which we have to:

$140 lb = 63.5 kg \rightarrow 63.5kg (9.8m/s) =622.3 N$

$120 lb = 54.4 kg \rightarrow 54.4kg (9.8m/s)= 533 N$

$170 lb = 77.1 kg \rightarrow 77.1 kg (9.8m/s) =756 N$

PART A ) From the given values the minimum acceleration will be given for 120Lb and maximum acceleration when 170Lb is reached therefore:

$F = 756 - 622.3$

$F = 133.7N$

Through the Newtonian relationship of the Force we have to:

$F= ma$

$a = \frac{F}{m}$

$a = \frac{133.7}{63.5}$

$a = 2.1m/s^2$

PART B) For the maximum magnitude of the acceleration downward we have that:

$F = 622.3 - 533$

$F = 89.3N$

Through the Newtonian relationship of the Force we have to:

$F= ma$

$a = \frac{F}{m}$

$a = \frac{89.3}{63.5}$

$a = 2.1m/s^2$

$a = 1.04 m/s^2$

7 0

2 years ago

Katie rolls a toy car off the end of a table.

hoa [83]

Answer: C.

Explanation:

i choose B and got it wrong it told me the answer after on edge.

4 0

2 years ago

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What are some other examples of scientific knowledge that must have resulted from indirect evidence?

n200080 [17]

Answer:

The atomic model, the structure of the solar system, and the theory of black holes are examples of models created using indirect evidence.

Explanation:

I have no explanation sorry.

5 0

2 years ago

A professor's office door is 0.99 m wide, 2.2 m high, 4.2 cm thick; has a mass of 27 kg, and pivots on frictionless hinges. A "d

ANEK [815]

Answer:

$I=8.8209\ kg.m^2$

$\alpha=0.6348\ rad.s^{-2}$

Explanation:

Given:

width of door, $w=0.99\ m$

height of the door, $h=2.2\ m$

thickness of the door, $t=4.2\ cm$

mass of the door, $m=27\ kg$

torque on the door, $\tau=5.6\ N.m$

<em>∵Since the thickness of the door is very less as compared to its other dimensions, therefore we treat it as a rectangular sheet.</em>

For a rectangular sheet we have the mass moment of inertia inertia as:

$I=\frac{1}{3} m.w^2$

$I=\frac{1}{3}\times 27\times 0.99^2$

$I=8.8209\ kg.m^2$

We have a relation between mass moment of inertia, torque and angular acceleration as:

$\alpha=\frac{\tau}{I}$

$\alpha=\frac{5.6}{8.8209}$

$\alpha=0.6348\ rad.s^{-2}$

6 0

2 years ago