a certain projetor uses a concave mirror for projecting an object's image on a screen .it produces on image that is 4 times bigger than the object and the screen is 5 m away from the mirror as shown in fig 5.2, calculate the focal length of the mirror.​

Answers

Answer 1

Answer:

f = 1 m

Explanation:

The magnification of the lens is given by the formula:

[tex]M = \frac{q}{p}[/tex]

where,

M = Magnification = 4

q = image distance = 5 m

p = object distance = ?

Therefore,

[tex]4 = \frac{5\ m}{p}\\\\p = \frac{5\ m}{4}\\\\p = 1.25\ m[/tex]

Now using thin lens formula:

[tex]\frac{1}{f}=\frac{1}{p}+\frac{1}{q}\\\\\frac{1}{f} = \frac{1}{1.25\ m}+\frac{1}{5\ m}\\\\\frac{1}{f} = 1\ m^{-1}\\\\[/tex]

f = 1 m


Related Questions

A circular parallel-plate capacitor whose plates have a radius of 25 cm is being charged with a current of 1.3 A. What is the magnetic field 11 cm from the center of the plates

Answers

The magnetic field at 11 cm from the center of the plates is 2.364 x 10⁻⁷ T.

Given;

radius of the circular plate, d = 25 cm = 0.25 m

current in the plate, I = 1.3 A

distance from the center of the circular plate, r = 11 cm = 0.11 m

To find:

magnetic field (B)

The magnetic field from the given distance is calculated as from Biot Savart equation:

[tex]B = \frac{\mu_o I}{2\pi r} \\\\where;\\\\\mu_o \ is \ permeability \ of \ free \ space \ 4\pi \times 10^{-7} \ T.m/A\\\\B = \frac{(4\pi \times 10^{-7} ) \times (1.3)}{2\pi \times 0.11} \\\\B = 2.364 \ \times 10^{-6} \ T[/tex]

Therefore, the magnetic field 11 cm from the center of the plates is 2.364 x 10⁻⁷ T.

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Which circuit element is of special importance in AC circuits?
A. Resistor
B. Ammeter
C. Battery
D. Capacitor​

Answers

Answer:

Explanation:capacitor

Answer:

Ammeter

Explanation:

pls mark me as a brainlist

need help with question after number 40

Answers

Answer:

4 device 3 e e and 4 divide 3 + 5 barabar 11 33 size to 46 size 35 and size 49 browser

HELP ME ASAP PLSSS!!​

Answers

I hope this helped !

A uniform electric field of strength E points to the right. An electron is fired with a velocity v0 to the right and travels a distance d before coming to a stop. An second electron is then fired upwards through the same field at a velocity of v0. After the electron moving vertical has traveled vertically upwards a distance d, how far will it have moved horizontally?

Answers

Answer:

[tex]D_l=d[/tex]

Explanation:

From the question we are told that:

The Electric field of strength direction =Right

The Velocity of The First Electron=V_0

The Velocity of The Second Electron=V_0

Therefore

[tex]V_{e1}=V_{e2}[/tex]

Generally, the equation for the Horizontal Displacement of electron is mathematically given by

[tex]D=\frac{at^2}{2}[/tex]

Where

Acceleration is given as

[tex]a=\frac{V_o}{2d}[/tex]

And

Time

[tex]T=\frac{d}{v_0}[/tex]

Therefore horizontal displacement towards the left is

[tex]D_l=\frac{(\frac{V_o}{2d})(\frac{d}{v_0})^2}{2}[/tex]

[tex]D_l=d[/tex]

Which of the following is a form of mechanical energy?
A. Chemical energy
B. Gravitational potential energy
C. Thermal energy
D. Nuclear energy

Answers

Answer:

B

Explanation:

no reason for this answer

B. Gravitational potential energy

Can someone log into my acc FOR ME I will pay you to complete my physics assignments for money or points?!!

Answers

Answer: no sorry../

Explanation:

Define hydropower or hydroelectric power ?
No Spam..

Answers

[tex]\:[/tex]

Hydroelectric power, also called hydropower is the electricity produced from generators driven by turbines that convert the potential energy of falling or fast-flowing water into mechanical energy.

Answer:

Hydroelectric power/hydropower -  electricity produced by a hydraulic source, specifically energy generated falling or flowing water

A circular loop of wire 10 cm in radius carries a current of 20 A. The axial magnetic field 15 cm from the center of the loop is approximately:

a. 37 mu-T
b. 13 mu-T
c. 21 mu-T
d. 41 mu-T
e. 18 mu-T]

Answers

Answer:

ans is c

Explanation:

chk photo

The axial magnetic field 15 cm from the center of the loop is approximately 21 μT. Hence, option (c) is correct.

What is magnetic field?

In the vicinity of a magnet, an electric current, or a shifting electric field, there is a vector field called a magnetic field where magnetic forces can be seen. Electric charges in motion and the intrinsic magnetic moments of elementary particles connected to the fundamental quantum characteristic known as spin create a magnetic field.

Given parameters:

Radius of the circular loop: r = 10 cm = 0.10 m.

Current passing through the loop: I = 20 A.

Axial distance of the point: z = 15 cm = 0.15 m.

Hence, the axial magnetic field at that point:

B = (μ₀/4π) 2πR²I/(z²+R²)^(3/2)

By putting these values, we get B = 21 × 10⁻⁶ T = 21 μT.

Learn more about magnetic field here:

https://brainly.com/question/14848188

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There was a major collision of an asteroid with the Moon in medieval times. It was described by monks at Canterbury Cathedral in England as a red glow on and around the Moon. How long after the asteroid hit the Moon, which is 3.84 x 10^5 km away, would the light first arrive on Earth?

Answers

Answer:

c = 3.00E108 m/s = 3.00E5 km/s

t = S / v = 3.84E5 / 3.00E5 = 1.28 sec

A T-shirt is launched at an angle of 30° with an initial velocity of 25 m/s how long does it take to reach the peak? How long is it in the air for totally?

Answers

Answer:

The launched angle θ = 30 degrees, the initial velocity Vo = 20 m/s, the initial horizontal velocity Vox= ?, the initial vertical velocity Voy = ?, the time of flight t = ? the maximum height h = ?

Vox = Vo * (cos of 30 degrees)

Voy = Vo * (sin of 30 degrees)

t = 2 * (Voy / g)

h = Voy * 0.5 t - 1/2 g * (0.5t)^2

I have given the equations for you to use, just plug – in the values and then solve in a step by step manner.

Answer:

approximately 15.68 meters.

Explanation:

Here is how;

First, let's calculate the time of flight for the t-shirt. We can use the vertical motion equation:

y = y0 + v0y * t - 0.5 * g * t^2

where:

y is the vertical displacement (27.7 m)

y0 is the initial vertical position (0 m)

v0y is the vertical component of the initial velocity (v0 * sin(theta))

g is the acceleration due to gravity (9.8 m/s^2)

t is the time of flight

Plugging in the values:

27.7 = 0 + (25.8 * sin(63.6°)) * t - 0.5 * 9.8 * t^2

Simplifying the equation, we get a quadratic equation:

4.9t^2 - (25.8 * sin(63.6°))t + 27.7 = 0

Solving this quadratic equation will give us the time of flight, t. Using the quadratic formula, we find that:

t ≈ 1.23 s

Now, let's find the horizontal displacement of the t-shirt using the horizontal motion equation:

x = x0 + v0x * t

where:

x is the horizontal displacement

x0 is the initial horizontal position (0 m)

v0x is the horizontal component of the initial velocity (v0 * cos(theta))

t is the time of flight

Plugging in the values:

x = 0 + (25.8 * cos(63.6°)) * 1.23

Calculating this:

x ≈ 14.92 m

The t-shirt falls short of reaching the person by the horizontal distance of:

Shortfall = 30.6 m - 14.92 m

Calculating this:

Shortfall ≈ 15.68 m

Therefore, the t-shirt will be approximately 15.68 meters short of reaching the person.

The average human walks at a speed of 5km per hour if your PE teacher asks you to walk for 30 minutes in gym class how far would you walk(km)?

Answers

Answer:

2.5 km

Explanation:

Answer:

2.5 km

Explanation:

Distance = speed x time

So =5 x 0.5

A plastic dowel has a Young's Modulus of 1.50 ✕ 1010 N/m2. Assume the dowel will break if more than 1.50 ✕ 108 N/m2 is exerted. What is the maximum force (in kN) that can be applied to the dowel assuming a diameter of 2.30 cm?

A.
52.3 kN

B.
62.3 kN

C.
72.3 kN

D.
42.3 N

Answers

Answer:

cobina

Explanation:

me 2

A cylindrical wire has a length of 2.80 m and a radius of 1.03 mm. It carries a current of current of 1.35 A, when a a voltage of 0.0320 V is applied across the ends of the wire. From this information calculate the resistance of the wire.

Answers

Answer:

0.023 Ohms

Explanation:

Given data

Length= 2.8m

radius= 1.03mm

current I= 1.35 A

voltage V= 0.032V

We know that from Ohm's law

V= IR

Now  R= V/I

Substitute

R= 0.032/1.35

R= 0.023 Ohms

Hence the resistance is 0.023 Ohms

A spherical balloon has a radius of 7.15 m and is filled with helium. The density of helium is 0.179 kg/m^3, and the density of air is 1.29 kg/m^3. The skin and structure of the balloon has a mass of 910 kg. Neglect the buoyant force on the cargo volume itself.
Determine the largest mass of cargo the balloon can lift.

Answers

The largest mass of cargo the balloon can lift is 791.06 kg

First, we need to calculate the mass of helium.

Since the radius of the spherical balloon is r = 7.15 m, its volume is V = 4πr³/3.

The volume of the balloon also equals the volume of helium present.

Now, the mass of helium m = density of helium, ρ × volume of helium, V

m = ρV

Since ρ = 0.179 kg/m³

m = ρV

m = ρ4πr³/3.

m = 0.179 kg/m³ × 4π(7.15 m)³/3

m = 0.179 kg/m³ × 4π(365.525875 m³)/3

m = 0.179 kg/m³ × 1462.1035π m³/3

m = 261.7165265π/3 kg

m = 822.207/3 kg

m = 274.07 kg

Since the mass of the skin and structure of the balloon is 910 kg, the total mass, M of the balloon = mass of skin and structure + mass of helium gas is 910 kg + 274.07 kg = 1184.07 kg.

The weight of this mass W = Mg where g = acceleration due to gravity.

The buoyant force on the balloon due to the air is the weight of air displaced, W' = mass of air, m' × acceleration due to gravity, g.

W' = m'g

Now, the mass of air m' = density of air, ρ' × volume of air displaced, V'

We know that the volume of air displaced, V' = volume of balloon, V

So, V' = V = 4πr³/3.

Since the density of air, ρ' = 1.29 kg/m³,

m' = ρ'V

m = 1.29 kg/m³ × 4π(7.15 m)³/3

m = 1.29 kg/m³ × 4π(365.525875 m³)/3

m = 1.29 kg/m³ × 1462.1035π m³/3

m = 1886.113515π/3 kg

m = 5925.4/3 kg

m = 1975.13 kg

So, the net weight W" that the balloon can lift is W" = W' - W = m'g - Mg = (m' - M )g = (1975.13 kg - 1184.07 kg)g = 791.06g.

So, the net mass m" = W"/g = 791.06g/g = 791.06 kg

This net mass is the largest mass of cargo that the balloon can lift.

Thus, the largest mass of cargo the balloon can lift is 791.06 kg

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A cowgirl ties one end of a 10.0 m long rope to a fence post (to the left of the cowgirl) and pulls on the other end so the rope is stretched horizontally with a tension of 140 N. The mass of the rope is

Answers

Answer:

Mass is zero if the whole rope is horizontal. Imaginary rope.

Explanation:

With any mass at all, only a small section of the rope will be truly horizontal. The rope curve will be a a catenary.

A 12-V battery is connected across a device with variable resisstance. As the resistance of the device increases, determine whether the following quantities increase, decrease, or remain unchanged. Indicate your answers with I, D, or U respectively.

a. The current through the device
b. The voltage across the device
c. The power consumed by the device

Answers

the answer is the current through the device

A bus moving on a straight road increases its speed uniformly from rest to 20m's over a time period of 1 min. The distance travelled during the time is (a) 150 m (b) 300 m (c) 600 m (d) 900 m​

Answers

Explanation:

Given that,

Initial velocity (u) = 0 m/sFinal velocity (v) = 20 m/sTime taken (t) = 1 minute = 60 seconds

In order to find the distance travelled, firstly we need calculate the acceleration.

v = u + at

→ 20 = 0 + 60a

→ 20 = 60a

→ 20 ÷ 60 = a

→ ⅓ m/s² = a

Now, by using the 2nd equation of motion :

s = ut + ½at²

→ s = 0(60) + ½ × ⅓ × (60)²

→ s = ⅙ × 3600

→ s = 1 × 600

→ s = 600 m

Hence, the distance travelled is 600 m.

Which technological device makes an energy conversion in the same way that a human ear makes an energy conversion?

a.) a loudspeaker

b.) a headphone

c.) a light bulb

d.) a microphone

I think it's c because of the concept of mechanical energy to electrical energy but I'm not sure

Answers

Answer:

I THINK C

Explanation:

BECAUSE A Light Emitting Diode (LED) glows even when a weak electric current passes through it.

A resistor is submerged in an insulated container of water. A voltage of 12 V is applied to the resistor resulting in a current of 1.2 A. If this voltage and current are maintained for 5 minutes, how much electrical energy is dissipated by the resistor

Answers

Explanation:

Given:

[tex]\Delta t = 5\:\text{min} = 300\:\text{s}[/tex]

[tex]V = 12 V[/tex]

[tex]I = 1.2 A[/tex]

Recall that power P is given by

[tex]P = VI[/tex]

so the amount of energy dissipated [tex]\Delta E[/tex] is given by

[tex]\Delta E = VI\Delta t = (12\:\text{V})(1.2\:\text{A})(300\:\text{s})[/tex]

[tex]\:\:\:\:\:\:\:= 4320\:\text{W} = 4.32\:\text{kW}[/tex]

How many types of physics?

Answers

Answer:

Two Main Branches of Physics

it is Classical Physics and Modern Physics.

Explanation:

Further sub Physics branches are Mechanics, Electromagnetism, Thermodynamics, Optics, etc. The rapid progress in science during recent years has become possible due to discoveries and inventions in the field of physics.

hope it helped

A roller coaster has a vertical loop with radius 25.7 m. With what minimum speed should the roller-coaster car be moving at the top of
the loop so that the passengers do not lose contact with the seats?
m/s

Answers

Answer:

15.88m/s

Explanation:

At the top of the roller coaster you will have three forces acting on the roller-coaster. See the image below. Fc is the centripetal force (for an object in circular motion), Fg is the gravitational force, and Fn is the normal force. To achieve the minimum speed we assume the roller-coaster is barely touching the vertical loop and so the normal force is zero. This leaves two acting forces.

[tex]F_g = F_c\\mg = \frac{m\times v^2}{r}\\v = \sqrt{gr} = \sqrt{9.81 \times 25.7} = 15.88 m/s[/tex]

A mirror forms an erect image 40cm from the object and one third its height where must the mirror be situated ​

Answers

image distance=-40cm=vObject distance=u=?Magnification=m=3

We know

[tex]\boxed{\sf m=-\dfrac{v}{u}}[/tex]

[tex]\\ \sf\longmapsto 3=-\dfrac{-40}{u}[/tex]

[tex]\\ \sf\longmapsto 3=\dfrac{40}{u}[/tex]

[tex]\\ \sf\longmapsto u=\dfrac{40}{3}[/tex]

[tex]\\ \sf\longmapsto u=13.3cm[/tex]

A solid metal sphere of radius 3 m carries a total charge of -5.5 uc. What is the magnitude of the
electric field at a distance from the sphere's center of (a) 2.9 m and (b) 8 m? How would the answers
differ if the sphere was (c) a thin shell.
IN​

Answers

Answer:

2.9::: 5.87*10*3 N/C

8: 7.73 × 10 ^2  N/C

Explanation: https://study.com/academy/answer/a-solid-metal-sphere-of-radius-3-00-m-carries-a-total-charge-of-5-50-muc-what-is-the-magnitude-of-the-electric-field-at-each-of-the-following-distances-from-the-sphere-s-center-a-3-10-m-b-8-00-m.html

A rugby player passes the ball 7.00 m across the field, where it is caught at the same height as it left his hand.
(a) At what angle was the ball thrown if its initial speed was 12.0 m/ s, assuming that the smaller of the two possible angles was used?
(b) What other angle gives the same range, and why would it not be used?
(c) How long did this pass take?

Answers

Answer:

a)   θ = 14.23º, b)   θ₂ = 75.77,  c) t = 0.6019 s

Explanation:

This is a missile throwing exercise.

a) the reach of the ball is the distance traveled for the same departure height

          R = [tex]\frac{v_o^2 \ sin 2 \theta }{g}[/tex]

          sin 2θ = [tex]\frac{Rg}{v_o^2}[/tex]

          sin 2θ = 7.00 9.8 / 12.0²

          2θ = sin⁻¹ (0.476389) = 28.45º

           θ = 14.23º

the complementary angle that gives the same range is the angle after 45 that the same value is missing to reach 90º

          θ ’= 90  -14.23

          θ’= 75.77º

b) the two angles that give the same range are

         θ₁ = 14.23

         θ₂ = 75.77

the greater angle has a much greater height so the time of the movement is greater and has a greater chance of being intercepted by the other team.

C) the time of the pass can be calculated with the expression

                       

           x = v₀ₓ t

           t = x / v₀ₓ

           t = 7 / 11.63

           t = 0.6019 s

Xác định ứng lực trong các thanh BC,
CF và FE của hệ giàn và chỉ rõ các thanh
chịu kéo hay nén. Cho P1=P2=600 lb,
P3=800 lb

Answers

Answer:

............................................

Explanation:

a youthful person run at 7km/h in a north- west direction across the derk of a ship in which is streaming due east at 40 km/h .ifind the velocity of the boy relative to the Sea
ii,And the velocity of the sea relative to the boy​

Answers

Answer:

velocity of ship wrt sea= 7i∧

velocity of women on deck= 40j∧

velocity of women relative to sea will be resultant of above two velocoties,

7i∧ + 40j∧ magnitude is

square root (7 x 7 + 40x40)

=√49+1600

=√1612

=40.14 m/s


Which wave has the highest frequency when traveling through the indicated metal?
Wavelength of 2.1 m in copper
Wavelength of 1.4 m in lead
Wavelength of 0.9 m in brass
Wavelength of 1.8 m in gold

Answers

Answer:

wavelength of 1.4in lead

Answer:

0.9

Explanation:

Chase grew up wanting to wear his sister's dresses over his brother's pants and button up shirts. When Chase turns 18, he decides to begin living as woman, though he's still only sexually attracted to women. He decides he doesn't want to undergo surgery. Chase is

Answers

Explanation:

she is a woman, i dont understand why youre still using he/him after she comes out

Describe sound and record​

Answers

Answer:

record is information created, received and maintained as evidence and information by an organization or person.in simpler terms it's a collection of of fields probably of different data types.

sound is however something loud or soft.which can be defined as vibrations that travel through the air or another medium.

I hope this helps

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