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3 years ago

What is the use of 'ground' in electric circuit?

1 answer:

5 0

In electrical engineering, ground or earth is the reference point in an electrical circuit from which voltages are measured, a common return path for electric current, or a direct physical connection to the earth. Electrical circuits may be connected to ground (earth) for several reasons.

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I need the answer right now pls help me

yaroslaw [1]

The AREA of the shaded region is the moving object's displacement.

7 0

3 years ago

What phenomenon reduces the adverse effects and pressure imposed by solar wind on earth?

inessss [21]

Answer:

The earths magnetic field

Explanation:

3 0

3 years ago

Consider a father pushing a child on a playground merry-go-round. The system has a moment of inertia of 84.4 kg.m^2. The father

Sophie [7]

Answer:

Explanation:

Given that:

the initial angular velocity $\omega_o = 0$

angular acceleration $\alpha$ = 4.44 rad/s²

Using the formula:

$\omega = \omega_o+ \alpha t$

Making t the subject of the formula:

$t= \dfrac{\omega- \omega_o}{ \alpha }$

where;

$\omega = 1.53 \ rad/s^2$

∴

$t= \dfrac{1.53-0}{4.44 }$

t = 0.345 s

Using the formula:

$\omega ^2 = \omega _o^2 + 2 \alpha \theta$

here;

$\theta$ = angular displacement

∴

$\theta = \dfrac{\omega^2 - \omega_o^2}{2 \alpha }$

$\theta = \dfrac{(1.53)^2 -0^2}{2 (4.44) }$

$\theta =0.264 \ rad$

Recall that:

2π rad = 1 revolution

Then;

0.264 rad = (x) revolution

$x = \dfrac{0.264 \times 1}{2 \pi}$

x = 0.042 revolutions

Here; force = 270 N

radius = 1.20 m

The torque = F * r

$\tau = 270 \times 1.20 \\ \\ \tau = 324 \ Nm$

However;

From the moment of inertia;

$Torque( \tau) = I \alpha \\ \\ Since( I \alpha) = 324 \ Nm. \\ \\ Then; \\ \\ \alpha= \dfrac{324}{I}$

given that;

I = 84.4 kg.m²

$\alpha= \dfrac{324}{84.4} \\ \\ \alpha=3.84 \ rad/s^2$

For re-tardation; $\alpha=-3.84 \ rad/s^2$

Using the equation

$t= \dfrac{\omega- \omega_o}{ \alpha }$

$t= \dfrac{0-1.53}{ -3.84 }$

$t= \dfrac{1.53}{ 3.84 }$

t = 0.398s

The required time it takes= 0.398s

5 0

3 years ago

A potato and raisins salad has been warmed up to a temperature of 80∘C80∘C and let it stand for three minutes. Then one tries a

barxatty [35]

Answer : The correct option is, (a) No. Potatoes will be warmer.

Explanation :

Formula used :

$Q=m\times c\times \Delta T$

where,

Q = heat taken

m = mass of substance

c = specific heat of substance = ?

$\Delta T$ = change in temperature

As we are given that the potatoes have a specific heat of $3430J/(kg^oC)$ and raisins have a specific heat of $1630J/(kg^oC)$ . That means higher the value of specific heat the more heat taken by the substance (more warmer will be the substance). So, the potatoes will be more warmer as compared to raisins.

Hence, the correct option is, (a) No. Potatoes will be warmer.

6 0

3 years ago

Rebecca heated 50mL of water from 0 degrees Celsius to 60 degrees Celsius. How much energy did she use to heat the water? Rememb

kramer

Answer:

12552 J or 3000 calories

Explanation:

Q = m × c × ∆T

Where;

Q = amount of heat energy (J)

m = mass of water (g)

c = specific heat capacity (4.184 J/g°C)

∆T = change in temperature

For 50mL of water, there are 50g, hence, m = 50g, c = 4.184 J/g°C, initial temperature = 0°C, final temperature = 60°C.

Q = m × c × ∆T

Q = 50 × 4.184 × (60 - 0)

Q = 209.2 × 60

Q = 12552 J

Hence, the amount of heat energy used to heat the water is 12552 J or 3000 calories

3 0

3 years ago