Need help pls and explain also

1. A 2,000-turn solenoid is 65 cm long and has cross-sectional area 30 cm2. What rate of change of current will produce a 600 Vo

JulsSmile [24]

Answer:

$\frac{dI}{dt} = 2.59\ x\ 10^4\ A/s$

Explanation:

First, we will calculate the inductance of the solenoid by using the following formula:

$L = \frac{\mu_o AN^2}{l}$

where,

L = self-inductance of solenoid = ?

μ₀ = permeability of free space = 4π x 10⁻⁷ N/A²

A = Cross-sectional area = 30 cm² = 3 x 10⁻³ m²

N = No. of turns = 2000

l = length = 65 cm = 0.65 m

Therefore,

$L = \frac{(4\pi\ x\ 10^{-7}\ N/A^2)(3\ x\ 10^{-3}\ m^2)(2000)^2}{0.65\ m}\\\\L = 0.0232\ H$

Now, we will use Faraday's law to calculate the rate of change of current:

$emf = L\frac{dI}{dt}\\\\ \frac{dI}{dt} =\frac{emf}{L} \\\\ \frac{dI}{dt} =\frac{600\ V}{0.0232\ H}\\\\ \frac{dI}{dt} = 2.59\ x\ 10^4\ A/s$

5 0

3 years ago

An object with a mass of 20 kg has a net force of 80 N acting on it. What is the acceleration of the object?

alexdok [17]

Newton's 2nd law of motion says

Net force = (mass) x (acceleration)

Plug in the things you know, and you have

80 N = (20 kg) x (acceleration)

Divide each side by (20 kg) :

80N / 20kg = acceleration

acceleration = 4 m/s²

4 0

3 years ago

Read 2 more answers

Two spectators at a soccer game in Montjuic Stadium see, and a moment later hear, the ball being kicked on the playing field. Th

NikAS [45]

Answer:

a) 68.943 m

b) 41.846 m

c) 80.648 m

Explanation:

Given:

Delay in time for spectator A, t₁ = 0.201 s

Delay in time for spectator B, t₂ = 0.122 s

the delay in sound heard is the due to the distance being traveled by the sound from the kicker to the spectator

thus,

a) Distance of the kicker from A,

d₁ = speed of sound × time taken

d₁ = 343 m/s × 0.201 s = 68.943 m

b) Distance of the kicker from B,

d₂ = speed of sound × time taken

d₂ = 343 m/s × 0.122 = 41.846 m

c) Since the angle between the two spectators for the player is 90°

thus, a right angles triangle is formed.

where, the distance between the spectators is the hypotenuses (s) of the so formed triangle

Therefore,

s² = d₁² + d₂²

on substituting the values, we get

s² = 68.943² + 41.846²

or

s² = 6504.22

or

s = √6504.22

or

s = 80.648 m

hence, the distance between the spectators is 80.648 m

3 0

3 years ago

A few alpha particles bounce off a thin sheet of gold foil. What did scientists

Vilka [71]

Answer:

I world say A is the answer 80% sure

7 0

2 years ago

An insulated rigid tank initially contains 1.4-kg saturated liquid water and water vapor at 200°C. At this state, 25 percent of

Elan Coil [88]

Solution:

Mass of liquid water and water vapor in the insulated tank initially = 1.4 kg

Temperature = 200 °C

And 25% of the volume by liquid water is steam.

State 1

$m=\frac{V}{v}$

$m=m_f+m_g$

$1.4=\frac{0.25V}{v_f}+\frac{0.75V}{v_g}$

$1.4=\frac{0.25V}{1.1565 \times 10^{-3}}+\frac{0.75V}{0.1274}$ (taking the value of $v_g$ and $v_g$ at 200°C )

$V=6.304 \times 10^{-3}$

Now quality of vapor

$x=\frac{m_g}{m}$

$=3.377 \times 10^{-3}$

Internal energy at state 1 can be found out by

$u_1=u_f+xu_{fg}$

$=850.65+3.377\times10^{-3}\times 1744.65$

= 856.54 kJ/kg

After heating with the resistor for 20 minutes, at state 2, the tank contains saturated water vapor $v_2=v_g \text { and }\ x=1$

Tank is rigid, so volume of tank is constant.

$v_g=v_2=\frac{V}{m}$

$v_g=\frac{6.304\times 10^{-3}}{1.4}$

$v_g=4.502 \times 10^{-3} \ m^3 /kg$

Now interpolate the value to get temperature at state 2 with specific volume value to get final temperature

$T_2=360+(374.14-360)\left(\frac{0.004502-0.006945}{0.003155-0.006945}\right)$

= 369.11° C

Internal energy at state 2

$u_2=2154.9 \ kJ/kg$

Now power rating of the resistor

$P=\frac{m(u_2-u_1)}{t}$

$P=\frac{1.4(2154.9-856.54)}{20 \times 60}$

= 1.51 kW

6 0

3 years ago