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3 years ago

A. How much work is done by a man standing with a load of 100 kg?ANS=0

Physics

1 answer:

damaskus [11]3 years ago

7 0

Explanation:

W = Fd

W for work

F for force

D for displacement

Since the man did not move nor did he move anything, the displacement is 0, thus work is 0 no matter what the force is

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provides one model for solving this problem. The maximum strength of the earth's magnetic field is about 6.9 x 10-5 T near the s

jeka57 [31]

Answer:

The minimum no. of turns is $3.126 \times 10^{5}$

Explanation:

Given:

Magnetic field $B = 6.9 \times 10^{-5}$ T

Frequency $f = 84.5$ Hz

Area of turn $A = 0.021$ $m^{2}$

Voltage $V_{rms} = 170$ V

From the formula of induced emf,

$V = NBA \omega$

Where $\omega = 2\pi f$ and $V = \sqrt{2} V_{rms}$

So number of turn is,

$N = \frac{\sqrt{2} V_{rms} }{AB2\pi f }$

$N = \frac{\sqrt{2} \times 170 }{0.021 \times 6.9 \times 10^{-5} \times 6.28 \times 84.5 }$

$N = 3.126 \times 10^{5}$

Therefore, the minimum no. of turns is $3.126 \times 10^{5}$

4 0

3 years ago

A non-ideal 12.2 V battery is connected across a resistor R. The internal resistance of the battery is 1.9Ohm. Calculate the pot

Brums [2.3K]

Answer:

R=100 Ohm, V=11.97 volts and I=0.12 amperes

R=10 Ohm, V=10.25 volts and I=1.20 amperes

R=2 Ohm, V=6.26 volts

Explanation:

The potential difference (voltage) of a battery with internal resistance is:

$V=\xi-Ir$ (1)

with $\xi$ the electromotive force (the voltage the batteries say to has) , I the current and r the internal resistance. By Ohm's law the current that passes through the resistor is:

$I=\frac{V}{R}$ (2)

using (2) on (1):

$V=\xi-\frac{V*r}{R}$

solving for V:

$V+\frac{V*r}{R}=\xi$

$V=\frac{\xi}{1+\frac{r}{R}}$ (3)

R=100 Ohm

$V=\frac{12.2}{1+\frac{1.9}{100}}=11.97 V$

R=10 Ohm

$V=\frac{12.2}{1+\frac{1.9}{10}}=10.25 V$

R=2 Ohm

$V=\frac{12.2}{1+\frac{1.9}{2}}=6.26 V$

Because we have now the values of I on the circuit (is the same through all the components because is a series circuit)

We use back substitution on (1) to find the current:

R=100 Ohm

$I=\frac{V}{R}=\frac{11.97}{100}=0.12 A$

R=10 Ohm

$I=\frac{V}{R}=\frac{11.97}{10}=1.20 A$

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3 years ago

Can plantlife affect the flow of water in a watershed?

Dmitry [639]

When it rains, water will flow into its appropriate watershed. A ridge or topographical higher areas that connects two waters are called a divide. In the United States there is an area in the Rocky Mountain called the "continental divide." This refers to water on the east of the divide flows into the Atlantic. The water on the west side flows into the Pacific

5 0

3 years ago

A man pulls on a (massless) rope tied to a tree with a force of 500 N. Later, two men pull on opposite ends of the same rope wit

qwelly [4]

Answer:

In both cases the tension in the rope is equal to 500N

Explanation:

It may be that in the case of the tree, the result is more intuitive, because you can think that there is only one force. But this is misleading.

To find the tension in the rope, you should draw a free body diagram. By doing so, you would find that the rope is static because there are two opposite forces. Assuming, for simplicity, that the rope is horizontal, a force of 500N is pulling to one direction (let's say to the right) and a force of 500N is pulling to the opposite direction (to the left). Else, the rope would not be static.

That analysys is the same for the rope tied to the tree ( the tree is pulling with 500N, such as the man, but in opposite direction) and when the rope is pulled by two men on opposite ends, each with forces of 500N.

Hence, the tension is the same and equal to 500N.

7 0

3 years ago

Read 2 more answers

What is the energy (in joules) and the wavelength (in meters) of the line in the spectrum of hydrogen that represents the moveme

soldi70 [24.7K]

Answer:

The energy is $4.57x10^{-19} J$ and the wavelength is $4.34x10^{-7}m$ for the line in the spectrum of hydrogen that represents the movement of an electron from Bohr orbit with n = 2 to the orbit with n = 5.

In what part of the electromagnetic spectrum do we find this radiation?

In the Ultraviolet part of the electromagnetic spectrum.

Explanation:

The energy of the absorbed photon can be known by the difference in energy between the two states in which the transition is happening (In this case from n = 2 to n = 5):

$E = E_{upper}-E_{lower}$ (1)

The permitted energy for the atom of hydrogen, according with the Bohr's model, is defined as:

$E_{n} = -\frac{13.606 eV}{n^{2}}$ (2)

Or it can be expressed in Joules, since $1eV = 1.60x10^{-19}J$

$E_{n} = -\frac{2.18x10^{-18} J}{n^{2}}$ (3)

Where the value $-2.18x10^{-18}$ represents the energy of the ground state¹ and n is the principal quantum number.

For the case of n = 2:

$E_{2} = -\frac{2.18x10^{-18} J}{(2)^{2}}$

$E_{2} = -5.45x10^{-19} J$

For the case of n = 5:

$E_{5} = -\frac{2.18x10^{-18} J}{(5)^{2}}$

$E_{5} = -8.72x10^{-20} J$

Replacing those values in equation (1) it is gotten:

$E = -8.72x10^{-20} J-(-5.45x10^{-19} J )$

$E = 4.57x10^{-19} J$

The wavelength can be determined by means of the Rydberg formula:

$\frac{1}{\lambda} = R(\frac{1}{n_{l}^{2}}-\frac{1}{n_{u}^{2}})$ (4)

Where R is the Rydberg constant, with a value of $1.097x10^{7}m^{-1}$

For this particular case $n_{l} = 2$ and $n_{u} = 5$ :

$\frac{1}{\lambda} = 1.097x10^{7}m^{-1}(\frac{1}{(2)^{2}}-\frac{1}{(5)^{2}})$

$\frac{1}{\lambda} = 1.097x10^{7}m^{-1}(0.21)$

$\frac{1}{\lambda} = 2303700m^{-1}$

$\lambda = \frac{1}{2303700m^{-1}}$

$\lambda = 4.34x10^{-7}m$

So the energy is $4.57x10^{-19} J$ and the wavelength is $4.34x10^{-7}m$ for the line in the spectrum of hydrogen that represents the movement of an electron from Bohr orbit with n = 2 to the orbit with n = 5.

In what part of the electromagnetic spectrum do we find this radiation?

In the Ultraviolet part of the electromagnetic spectrum.

Key terms:

¹Ground state: State of minimum energy.

8 0

3 years ago

A. How much work is done by a man standing with a load of 100 kg?ANS=0​

A. How much work is done by a man standing with a load of 100 kg?ANS=0