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3 years ago

BRAINLIESTTT!! HELP ME!!!

Physics

1 answer:

likoan [24]3 years ago

6 0

The efficiency of the scissor is 200%.

<u>Explanation:</u>

Efficiency is defined as the ratio of output of any instrument or device or machine to the input supplied to it. So the greater the output the greater will be the efficiency of the device.

As here the work done by us on the system is said to be 10 J so this will be equal to the input work done on the system. And the work done by the system i.e., the scissor is 20 J, so this will be the output work.

So, the efficiency is the ratio of output to input as shown below.

Efficiency = $(\frac {20} {10} ) \times 100$ = 200

So, the efficiency of the scissor is 200%.

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2 years ago

Marvin uses a long copper wire with resistivity 1.68 x 10^-8 Ω⋅m and diameter 1.00 x 10^−3 m to create a solenoid that has a 3

Mazyrski [523]

Answer with Explanation:

We are given that

Resistivity of copper wire= $\rh0=1.68\times 10^{-8}\Omega m$

Diameter=d= $1.00\times 10^{-3} m$

Radius of copper wire= $r=\frac{d}{2}=\frac{1}{2}\times 10^{-3} m$

Radius of solenoid=r' $=3 cm=3\times 10^{-2} m$

1 m=100 cm

a.Length of wire=l=11.3 m

Area of wire=A= $\pi r^2$

Where $\pi=3.14$

A= $3.14\times (\frac{1}{2}\times 10^{-3})^2$

Resistance, R= $\rho \frac{l}{A}$

Using the formula

$R=1.68\times 10^{-8}\times\frac{11.3}{3.14\times (\frac{1}{2}\times 10^{-3})^2}$

$R=0.24\Omega$

B.Length of solenoid= $2\pi r'=2\times 3.14\times 3\times 10^{-2}=0.188$ m

Number of turns= $n_0=\frac{l}{2\pi r'}=\frac{11.3}{0.188}$

$n_0$ =60

C.Potential difference,V=3 V

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

I= $\frac{3}{0.24}=12.5 A$

D.Total length =0.1 m

Number of turns per unit length,n= $\frac{60}{0.1}=600$

Magnetic field along central axis inside of the solenoid,B= $\mu_0 nI$

$B=4\pi\times 10^{-7}\times 12.5\times 600=9.42\times 10^{-3} T$

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3 years ago

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Which is the mode of the following data?<br>120, 125, 130, 125, 135

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4 years ago

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Find the magnitude of the emf induced in the rod when it is moving toward the right with a speed 7.50 m/s.

Flauer [41]

Answer:

3 volts

Explanation:

It is given that,

Magnetic field, B = 0.8 T

Length of a conducting rod, l = 50 cm = 0.5 m

Velocity of the conducting rod, v = 7.5 m/s

We need to find the magnitude of the emf induced in the rod when it is moving toward the right. When a rod is moved in a magnetic field, an emf is induced in it and it is given by :

$\epsilon=Blv$

Putting all the values,

$\epsilon=0.8\times 0.5\times 7.5\\\\\epsilon=3\ V$

So, the magnitude of the emf induced in the rod is 3 volts.

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3 years ago

13. Harry used the energy stored in his muscles to cycle up a hill. What happened to this energy when he reached the top?

nika2105 [10]

Answer:

C. Kinetic energy changed to potential energy.

Explanation:

The kinetic energy is converted to potential energy when he reaches the top of the hill.

As with every system, energy is neither created nor destroyed but transformed from one form to another.

This is from the law of conservation of energy.

Kinetic energy is produced when Harry moves the up the hill. As he reaches the top of the hill and comes to rest, potential energy is formed.

Potential energy is the energy due to the position of a body.

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