a point object is 10 cm away from a plane mirror while the eye of an observer(pupil diameter is 5.0 mm) is 28 cm a way assuming both eye and the point to be on the same line perpendicular to the surface find the area of the mirror used in observing the reflection of the point

Answer:

due to production of heat through friction

Explanation:

because of the friction produce between her hands

Answer:

to adjust from distant to the near objects

Explanation:

Answer:

The ability of eye lens to change the focal length of eye lens is called accommodation power of eye.

Explanation:

The human eye is the optical instrument which works on the refraction of light.

The ability of eye lens to change its focal length is called accommodation power of eye.

The focal length of eye lens is changed by the action of ciliary muscles.

When the ciliary muscles are relaxed then the thickness of lens is more and thus the focal length is small. When the ciliary muscles is stretched, the lens is thin and then the focal length is large.

Answer:

[tex]P_b = \frac{\rho_b}{\rho_a} \ P_a[/tex]

Explanation:

The pressure at a depth of a fluid is

       P = ρ g y

where ρ is the density of the fluid, y the depth of the gauge measured from the surface of the fluid.

In this case the pressure for fluid A is

      Pa = ρₐ g y

the pressure for fluid B is

      P_b = ρ_b g y

depth y not changes as the gauge is stationary

if we look for the relationship between these pressures

       [tex]\frac{P_a}{P_b} = \frac{ \rho_a}{\rho_b}[/tex]

        [tex]P_b = \frac{\rho_b}{\rho_a} \ P_a[/tex]

therefore we see that the pressure measured for fluid B is different from the pressure of fluid A

if  ρₐ < ρ_b B the pressure P_b is greater than the initial reading

   ρₐ>  ρ_b the pressure in B decreases with respect to the reading in liquid A

Answer:

Explanation:

An impulse results in a change of momentum.

The impulse is the product of a force and a distance. This will be represented by the area under the curve

a) W = ½(4.00)(3.00) = 6.00 J

b) W = (11.0 - 4.00)(3.00) = 21.0 J

c) W = ½(17.0 - 11.0)(3.00) = 9.00 J

d) ASSUMING the speed at x = 0 is in the direction of applied force

½(3.00)(v₄²) = ½(3.00)(0.450²) + 6.00

v₄ = 2.05 m/s

½(3.00)(v₁₇²) = ½(3.00)(0.450²) + 6.00 + 21.0 + 9.00

v₁₇ = 4.92 m/s

If the initial speed is NOT in the direction of applied force, the final speed will be slightly less in both cases.

Answer:

The vibrating length of the air column is greater than the actual length of the organ pipe

Answer:

ygguguguhhihhihijijijjojojinjbgy

Answer:

elevators

Theatre system

construction pulley

lifts

Answer:

elevator,cargo lift system

Answer:

h = 27.17 m

Explanation:

First, we will calculate the total mechanical energy of the system at the bottom point of the third loop:

Mechanical Energy = Kinetic Energy + Potential Energy

[tex]E = \frac{1}{2}mv^2 + mgh[/tex]

where,

E = Total Mechanical Energy = ?

m = mass of the roller coaster = 1200 kg

v = velocity of the roller coaster = 22 m/s

g = acceleration due to gravity = 9.81 m/s²

h = height of roller coaster = 2.5 m

Therefore,

[tex]E = \frac{1}{2}(1200\ kg)(22\ m/s)^2+(1200\ kg)(9.81\ m/s^2)(2.5\ m)\\\\E = 290400 J +29430\ J\\\\E = 319830\ J = 319.83\ KJ[/tex]

Now, the total mechanical energy at the top position of the first hill must also be the same:

[tex]E = \frac{1}{2}mv^2 + mgh[/tex]

where,

v = 0 m/s

h = ?

Therefore,

[tex]319830\ J = \frac{1}{2}(1200\ kg)(0\ m/s)^2+(1200\ kg)(9.81\ m/s^2)(h)\\\\h = \frac{319830\ J}{11772\ N}\\\\[/tex]

h = 27.17 m

Answer:

Increasing until terminal velocity is reached

Explanation:

Provided the scream is a constant pitch at the source, Doppler effect will make the pitch increase as the velocity of the source towards the listener increases.

Answer:

the radius of the bigger loop is 5 cm.

Explanation:

Given;

current in the smaller loop, I₁ = 12 A

current in the larger loop, I₂ = 20 A

radius of the smaller loop, r₁ = 3 cm

let the radius of the larger loop, = r₂

Apply Biot-Savart's law to determine the magnetic field at the center of the circular loops.

[tex]B= \frac{\mu_0 I}{2r}[/tex]

The magnetic field at the center of the smaller loop;

[tex]B_1 = \frac{\mu_0 I_1}{2 r_1}[/tex]

The magnetic field at the center of the bigger loop;

[tex]B_2 = \frac{\mu_0 I_2}{2 r_2}[/tex]

If the magnetic field at the center is zero, then B₁ = B₂

[tex]B_1 = B_2 = \frac{\mu_0 I_1}{2 r_1} = \frac{\mu_0 I_2}{2 r_2} \\\\\frac{I_1}{ r_1} = \frac{ I_2}{r_2} \\\\r_2 = \frac{I_2 r_1}{ I_1} = \frac{(20 \ A) \times (3.0 \ cm)}{12 \ A} = 5 \ cm[/tex]

Therefore, the radius of the bigger loop is 5 cm.

Answer:

The percentage of people who wanted both the swimming pool and the soccer complex is 0.6 + 0.6 – 0.95 = 0.25. This can also be seen in the Venn diagram.

Explanation:

Edmentum

We know

[tex]\boxed{\large{\sf Velocity=\dfrac{Distance}{Time}}}[/tex]

[tex]\\ \Large\sf\longmapsto Velocity=\dfrac{6}{\dfrac{1}{2}}[/tex]

[tex]\\ \Large\sf\longmapsto Velocity=6\times 2[/tex]

[tex]\\ \Large\sf\longmapsto Velocity=12km/h[/tex]

Is this the right answer??

We should keep km and min in smallest SI unit

Answer:

The results of the experiment indicated a shift consistent with zero, and certainly less than a twentieth of the shift expected if the Earth's velocity in orbit around the sun was the same as its velocity through the ether.

Explanation:

Answer:

A change in pressure at one point in an incompressible fluid is felt at every other point in the fluid.

Explanation:

Pascal's principle states that ''pressure applied to an enclosed fluid will be transmitted without a change in magnitude to every point of the fluid and to the walls of the container.''(Science direct).

The implication of this law is; that a change in pressure at one point in an incompressible fluid is felt at every other point in the fluid. Hence the correct answer chosen above.

The Pascal's principle is applied in hydraulic jacks and automobile brakes.

Answer:

The angular acceleration is 26.6 rad/s^2.

Explanation:

Force, F = 314 N

radius, r = 0.281 m

mass, m = 84.2 kg

The grindstone is a disc.

The torque is given by

torque = force x radius

Torque = 314 x 0.281 = 88.234 Nm

The torque is given by

Torque = Moment of inertia x angular acceleration

[tex]88.234 = 0.5 mr^2 \alpha \\\\88.234 = 0.5\times 84.2\times 0.281\times 0.281\times \alpha \\\\\alpha = 26.6 rad/s^2[/tex]

Answer:

[tex]N_f=248N[/tex]

Explanation:

From the question we are told that:

Mass [tex]m=100kg[/tex]

Ladder Length [tex]l=4.0m[/tex]

Mass of Ladder [tex]m_l=25kg[/tex]

Angle [tex]\theta=56 \textdegree[/tex]

Generally the equation for Co planar forces is mathematically given by

[tex]mgcos \theta *2+Mgcos\theta*1 -N_fsin \theta*4=0[/tex]

Therefore

[tex]25*9.81cos 56 *2+100*9.81cos56*1 -N_fsin 56*4=0[/tex]

[tex]N_f=248N[/tex]

Answer:

300J

Explanation:

Work done = Force x the distance travelled in the direction of the force

=300 x 1

=300J

i. [tex]T = 36.8\:\text{N}[/tex]

ii. [tex]a = 2.45\:\text{m/s}^2[/tex]

iii. [tex]x = 1.23\:\text{m}[/tex]

Explanation:

Let's write Newton's 2nd law for each object. We will use the sign convention assigned for each as indicated in the figure. Let T be the tension on the string and assume that the string is inextensible so that the two tensions on the strings are equal. Also, let a be the acceleration of the two masses. And [tex]m_1 = 3\:\text{kg}[/tex] and [tex]m_2 = 5\:\text{kg}[/tex]

Forces acting on m1:

[tex]T - m_1g = m_1a\:\:\:\:\:\:\:(1)[/tex]

Forces acting on m2:

[tex]m_2g - T = m_2a\:\:\:\:\:\:\:(2)[/tex]

Combining Eqn(1) and Eqn(2) together, the tensions will cancel out, giving us

[tex]m_2g - m_1g = m_2a + m_1a[/tex]

or

[tex](m_2 - m_1)g = (m2 + m_1)a[/tex]

Solving for a,

[tex]a = \left(\dfrac{m_2 - m_1}{m_2 + m_1}\right)g[/tex]

[tex]\:\:\:\:= \left(\dfrac{5\:\text{kg} - 3\:\text{kg}}{5\:\text{kg} + 3\:\text{kg}}\right)(9.8\:\text{m/s}^2)[/tex]

[tex]\:\:\:\:= 2.45\:\text{m/s}^2[/tex]

We can solve for the tension by using this value of acceleration on either Eqn(1) or Eqn(2). Let's use Eqn(1).

[tex]T - (3\:\text{kg})(9.8\:\text{m/s}^2) = (3\:\text{kg})(2.45\:\text{m/s}^2)[/tex]

[tex]T = (3\:\text{kg})(9.8\:\text{m/s}^2) + (3\:\text{kg})(2.45\:\text{m/s}^2)[/tex]

[tex]\:\:\:\:= 29.4\:\text{m/s}^2 + 7.35\:\text{m/s}^2 = 36.8\:\text{N}[/tex]

Assuming that the two objects start from rest, the distance that they travel after one second is given by

[tex]x = \frac{1}{2}at^2 = \frac{1}{2}(2.45\:\text{m/s}^2)(1\:\text{s})^2 = 1.23\:\text{m}[/tex]

Answer:

No. As we gain mass the force of gravity on us does not decrease

Answer:

The current in third branch is 11 A.

Explanation:

incoming current in one branch = 18 A

outgoing current in the other branch = 7 A

let the current in the third branch is i.

According to the Kirchoff's fist law in electricity

incoming current = out going current

18 = 7 + i

i = 11 A

The current in third branch is 11 A.

Answer:

L = 169.5 m

Explanation:

Using Ohm's Law:

V = IR

where,

V = Voltage = 1.5 V

I = Current = 10 mA = 0.01 A

R = Resistance = ?

Therefore,

1.5 V = (0.01 A)R

R = 150 Ω

But the resistance of a wire is given by the following formula:

[tex]R = \frac{\rho L}{A}[/tex]

where,

ρ = resistivity = 1 x 10⁻⁶ Ω.m

L = length of wire = ?

A = cross-sectional area of wire = πr² = π(0.6 mm)² = π(0.6 x 10⁻³ m)²

A = 1.13 x 10⁻⁶ m²

Therefore,

[tex]150\ \Omega = \frac{(1\ x\ 10^{-6}\ \Omega .m)L}{1.13\ x\ 10^{-6}\ m^2}\\\\L = \frac{150\ \Omega(1.13\ x\ 10^{-6}\ m^2)}{1\ x\ 10^{-6}\ \Omega .m}\\\\[/tex]

L = 169.5 m

Answer:

The unit of the time constant RC is the second

Explanation:

The unit of resistance, R is the Ohm, Ω and resistance, R = V/I where V = voltage and I = current. The unit of voltage is the volt, V while the unit of current is the ampere. A.

Since R = V/I

Unit of R = unit of V/unit of I

Unit of R = V/A

Ω = V/A

Also, The unit of capacitance, C is the Farad, F and capacitance, F = Q/V where Q = charge and V = voltage. the unit of charge is the coulomb, C while the unit of voltage is the volt, V

Since C = Q/V

Unit of C = unit of Q/unit of V

Unit of C = C/V

F = C/V

Now the time constant equals RC.

So, the unit of the time constant = unit of R × unit of C = Ω × F = V/A × C/V = C/A

Also. we know that the  1 Ampere = 1 Coulomb per second

1 A = 1 C/s

So, substituting 1 A in the denominator, we have

unit of RC =  C/A = C ÷ C/s = s

So, the unit of RC = s = second

So, the unit of the time constant RC is the second

Explanation:

Let [tex]\textbf{A} = 6\hat{\textbf{i}} + 4\hat{\textbf{j}} - 2\hat{\textbf{k}}[/tex] and [tex]\textbf{B} = 2\hat{\textbf{i}} - 2\hat{\textbf{j}} + 3\hat{\textbf{k}}[/tex]

The sum of the two vectors is

[tex]\textbf{A + B} = (6 + 2)\hat{\textbf{i}} + (4 - 2)\hat{\textbf{j}} + (-2 + 3)\hat{\textbf{k}}[/tex]

[tex] = 8\hat{\textbf{i}} + 2\hat{\textbf{j}} + \hat{\textbf{k}}[/tex]

The difference between the two vectors can be written as

[tex]\textbf{A - B} = (6 - 2)\hat{\textbf{i}} + (4 - (-2))\hat{\textbf{j}} + (-2 - 3)\hat{\textbf{k}}[/tex]

[tex]= 4\hat{\textbf{i}} + 6\hat{\textbf{j}} - 5\hat{\textbf{k}}[/tex]

Answer:

Magnification = 1

Explanation:

given data

radius of curvature r = - 0.983 m

image distance u = - 0.155

solution

we get here first focal length that is

Focal length, f = R/2     ...................1

f = -0.4915 m

we use here formula that is

[tex]\frac{1}{v} + \frac{1}{u} + \frac{1}{f}[/tex]      .................2

put here value and we get

[tex]\frac{1}{v} = \frac{1}{0.155} - \frac{1}{4915}[/tex]  

so

Magnification will be here as

m = [tex]- \frac{v}{u}[/tex]

m =  [tex]\frac{0.155}{0.155}[/tex]

Answer:

The magnification is 1.5.

Explanation:

radius of curvature, R = - 0.983 m

distance of object, u = - 0.155 m

Let the distance of image is v.

focal length, f = R/2 = - 0.492 m

Use the mirror equation

[tex]\frac{1}{f}=\frac{1}{v}+\frac {1}{u}\\\\\frac{-1}{0.492}=\frac{1}{v}-\frac{1}{0.155}\\\\\frac{1}{v}=\frac{1}{0.155}-\frac{1}{0.492}\\\\\frac{1}{v}=\frac{0.492-0.155}{0.155\times 0.492}\\\\\frac{1}{v}=\frac{0.337}{0.07626}\\ \\v = 0.226 m[/tex]

The magnification is given by

m = - v/u

m = 0.226/0.155

m = 1.5

285.3 days

Explanation:

The centripetal force [tex]F_c[/tex] experienced by the planet is the same as the gravitational force [tex]F_G[/tex] so we can write

[tex]F_c = F_G[/tex]

or

[tex]m\dfrac{v^2}{R} = G\dfrac{mM}{R^2}[/tex]

where M is the mass of the star and R is the orbital radius around the star. We know that

[tex]v = \dfrac{C}{T} = \dfrac{2\pi R}{T}[/tex]

where C is the orbital circumference and T is orbital period. We can then write

[tex]\dfrac{4\pi^2R}{T^2} = G\dfrac{M}{R^2}[/tex]

Isolating [tex]T^2[/tex], we get

[tex]T^2 = \dfrac{4\pi^2R^3}{GM}[/tex]

Taking the square root of the expression above, we get

[tex]T = 2\pi \sqrt{\dfrac{R^3}{GM}}[/tex]

which turns out to be [tex]T = 2.47×10^7\:\text{s}[/tex]. We can convert this into earth days as

[tex]T = 2.47×10^7\:\text{s}×\dfrac{1\:\text{hr}}{3600\:\text{s}}×\dfrac{1\:\text{day}}{24\:\text{hr}}[/tex]

[tex]\:\:\:\:\:= 285.3\:\text{days}[/tex]

Answer:

433.15K

Explanation:

(320°F − 32) × 5/9 + 273.15 = 433.15K

Answer:

A galvanometer is converted into an ammeter by connecting a low resistance in parallel with the galvanometer.

Explanation:

This low resistance is called shunt resistance S. The scale is now calibrated in ampere and the range of the ammeter depends on the values of the shunt resistance.

Answer:

Sources:

-- https://intblog.onspot.com/en-us/why-do-bridges-become-icy-before-roads

and

-- https://www.accuweather.com/en/accuweather-ready/why-bridges-freeze-before-roads/687262

I hope this helps you! ^^