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3 years ago

A voltage of 75 V is placed across a 150 Ω resistor. What is the current through the resistor?

Physics

1 answer:

Naddika [18.5K]3 years ago

6 0

Answer:

0.5 A

Explanation:

Applying,

V = IR.................. Equation 1

Where V = Voltage, I = current, R = Resistance.

make I the subject of the equation

I = V/R............... Equation 2

From the question,

Given: V = 75 V, R = 150 Ω

Substitute these values into equation 2

I = 75/150

I = 0.5 A.

Hence the cuurent through the resistor is 0.5 A

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How is vibrational motion connected to waves?

frozen [14]

Answer:

Explanation:

Waves and wave functions are direct ways to graph vibrational motion. Specifically, for cases dealing with vibrating strings. If you were to move a tensioned string up and down with your arm, you would produce a wave with a given frequency, period, and amplitude.

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2 years ago

Calculate the mechanical advantage of a pulley system if only 10 lb is required to lift a 500 lb block

ExtremeBDS [4]

As we know that mechanical advantage is defined as the ratio of output force and input force for the pulley system

Here we know that it required 10 lb of input force in order to lift the block of 500 lb so here output force is 500 lb

now we have

$MA = \frac{F_{out}}{F_{in}}$

here we have

$F_{out} = 500 lb$

$F_{in} = 10 lb$

now from above formula we have

$MA = \frac{500}{10}$

$MA = 50$

so mechanical advantage of this system is 50

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3 years ago

You stand on a straight desert road at night and observe a vehicle approaching. This vehicle is equipped with two small headligh

zhuklara [117]

Complete Question

You stand on a straight desert road at night and observe a vehicle approaching. This vehicle is equipped with two small headlights that are 0.681 m apart. At what distance, in kilometres, are you marginally able to discern that there are two headlights rather than a single light source?Take the wavelength of the light to be 549 nm and your pupil diameter as 4.63 mm.

Answer:

The distance is $z = 4707.6 \ m$

Explanation:

From the question we are told that

The is distance between the headlight is $d = 0.681 \ m$

The wavelength is $\lambda = 549 \ nm = 549 *10^{-9} \ m$

The pupil diameter is $D = 4.63 \ mm = 0.00463 \ m$

Generally, we can mathematically evaluate the resolution of the eye as

$\theta = \frac{1.22 * \lambda }{D}$

substituting values

$\theta = \frac{1.22 * 549 *10^{-9} }{0.00463}$

$\theta = (1.45 *10^{-4} )^o$

Now according to SOHCAHTOA rule

$sin \theta = \frac{ d}{z}$

Where z is the distance at which the eye can discern the two head light

given that the angle is very small $sin \theta = \theta$

=> $\theta = \frac{ d}{z}$

substituting values

$1.45*10^{-4} = \frac{ 0.681}{z}$

=> $z = \frac{0.681}{1.45 *10^{-4}}$

=> $z = 4707.6 \ m$

6 0

4 years ago

A piston having 7.23 g of steam at 110°C increases its temperature by 35°C. At the same time it expands from a volume of 2.00 L

My name is Ann [436]

Answer : The value of $q,w,\Delta U\text{ and }\Delta U$ is 505 J, -599 J, -94 J and -693 J respectively.

Explanation : Given,

Mass of steam = 7.23 g

Initial temperature = $110^oC$

Final temperature = $(110+35)^oC=145^oC$

Initial volume = 2 L

Final volume = 8 L

External pressure = 0.985 bar

Heat capacity of steam = 1.996 J/g.K

First law of thermodynamic : It states that the energy can not be created or destroyed, it can only change or transfer from one state to another state.

As per first law of thermodynamic,

$\Delta U=q+w$

First we have to calculate the heat absorbed by the system.

Formula used :

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

or,

$Q=m\times c\times (T_2-T_1)$

where,

Q = heat absorbed by the system = ?

m = mass of steam = 7.23 g

$C_p$ = heat capacity of steam = $1.966J/g.K$

$T_1$ = initial temperature = $110^oC=273+110=383K$

$T_2$ = final temperature = $145^oC=273+145=418K$

Now put all the given value in the above formula, we get:

$Q=7.23g\times 1.966J/g.K\times (418-383)K$

$Q=505J$

Now we have to calculate the work done.

Formula used :

$w=-p_{ext}dV\\\\w=-p_{ext}(V_2-V_1)$

where,

w = work done = ?

$p_{ext}$ = external pressure = 0.985 bar = 0.985 atm (1 bar = 1 atm)

$V_1$ = initial volume of gas = 2.00 L

$V_2$ = final volume of gas = 8.00 L

Now put all the given values in the above formula, we get :

$w=-p_{ext}(V_2-V_1)$

$w=-(0.985atm)\times (8.00-2.00)L$

$w=-5.91L.atm=-5.91\times 101.3J=-599J$

conversion used : (1 L.atm = 101.3 J)

Now we have to calculate the change in internal energy of the system.

$\Delta U=q+w$

$\Delta U=505J+(-599J)$

$\Delta U=-94J$

Now we have to calculate the change in enthalpy of the system.

Formula used :

$\Delta H=\Delta U+P\Delta V$

$\Delta H=\Delta U+w$

$\Delta H=(-94J)+(-599J)$

$\Delta H=-693J$

Therefore, the value of $q,w,\Delta U\text{ and }\Delta U$ is 505 J, -599 J, -94 J and -693 J respectively.

4 0

4 years ago

A beetle with a mass of 15.0 g is initially at rest on the outer edge of a horizontal turntable that is also initially at rest.

vichka [17]

Answer:

- 8.33 x 10⁻³ rad /s ( anticlockwise)

Explanation:

The rotational movement of beetle and turntable is caused by torque generated by internal forces , we can apply conservation of angular momentum.

That is ,

I₁ ω₁ = I₂ω₂ , ω₁ and ω₂ are angular velocity of beetle and turntable respectively.

ω₁ + ω₂ = .05 radian /s ( given )

Momentum of inertia of beetle I₁ = mass x (distance from axis)²

= 15 x 10⁻³ x R² ( R is radius of the turntable )

Momentum of inertia of turntable I₂ =1/2 mass x (distance from axis)²

= 75/2 x 10⁻³ x R² ( R is radius of the turntable )

I₁ ω₁ = I₂ω₂ ,

15 x 10⁻³ x R² x ( .05 - ω₂ ) = 75/2 x 10⁻³ x R² ω₂

15 x ( .05 - ω₂ ) = 75/2 x ω₂

.75 - 15ω₂ = 37.5ω₂

.75 = 52.5 ω₂

ω₂ = - 14.3 x 10⁻³ rad /s ( anticlockwise)

7 0

3 years ago