what is principal focus and focus length with examples​

Answers

Answer 1

Explanation:

Principle focus is the point on the axis of a convex lens, where the parallel rays of light from one side of the lens. meet on other side after refraction. Distance between optical centre to principle focus point is the focal length.


Related Questions

formula of average speed​

Answers

Answer:

Hey mate....

Explanation:

This is ur answer.....

Hope it helps!

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Mention theree disadvantages of friction
between
the parts of a
machine
How does. 1 . oiling
2 using ball bearing
3) Help recluce friction
pleaze help me to this question ​

Answers

Answer:

Please find the answer in the explanation.

Explanation:

Mention three disadvantages of friction between the parts of a machine

Three disadvantages of friction between the part of a machine are;

1. Friction causes wear and tear of machine parts.

2. Friction generates heat between the part of a machine.

3. Friction reduces the efficiency of a machine.

How does.

1 . oiling

2 using ball bearing

To reduce friction, you need to apply a lubricant. Oil and grease are examples of a lubricant. A lubricant helps to reduce friction by making the surface of the machine parts slippery thereby reducing tear and wear.

Also, friction can be reduced by using ball bearing which will allow the rolling of machine parts.


If a car is traveling 35 m/s for 200 seconds, how far will the car travel?

Answers

Hey I’m just setting up my profile so I’ll say fast

the mass of the earth is 6 × 10²² kg and that of the moon is 7.4× 10²² Kg if the distance between the earth and moon is 3.84 × 10⁵ km . calculate the force of the earth exerted by it on the moon . Take G = 6.67×10¹¹ Nm² / kg²​

Answers

Answer:

Force = 20.08 x 10⁴⁷ N

Explanation:

Given:

M1 = 6 × 10²⁴ kg (rectified)

M2 = 7.4× 10²² Kg

Radius r = 3.84 × 10⁵ km

G = 6.67×10¹¹ Nm² / kg²​

Find:

Force

Computation:

F = GM1M2 / r²

Force = [(6 × 10²⁴)(7.4× 10²²)(6.67×10¹¹ )] / (3.84 × 10⁵)²

Force = [296.148 × 10⁵⁷] / [14.7456 × 10¹⁰]

Force = 20.08 x 10⁴⁷ N

What is the difference between a bar magnet and an electromagnet? (check all that are
true)
A . A bar magnet is a permanent magnet that will keep its magnetism for a long time
B . An electromagnet is always stronger than a bar magnet.
C . A bar magnet will only stay a magnet if it is in contact with something metal.
D . An electromagnet is a temporary magnet that is only magnetic when electricity is flowing through the wire.

Answers

Answer:

D and A

Explanation:

Hint The basic difference between them is that a bar magnet is a permanent magnet whereas an electromagnet is a temporary magnet. An electromagnet is formed when an electric current is passed through wires wound around soft metalcore. An electromagnet loses its magnetism once the current flow is stopped.

A toy car, as shown below, is moving forward with a force of six Newton's. If the wind blows from behind with a force of two Newton's, what will happen to its speed and position

Answers

Answer:

its speed will increase to 8 newtons allowing its position to dramatically change.

If you walk at an average speed of 5 km/h for 30 minutes,
how far will you walk?

Answers

Answer:

150

Explanation:

30 times 5 = 150 i think

Una bola se lanza verticlamente de la parte superior de un edificio con una velocidad inicial 25 m/s la bola impacta al suelo en la base del edificio 7 segundos despues de ser lanzada ¿que altura subio la bola

Answers

Answer:

S = 415.1 meters

Explanation:

Dados los siguientes datos;

Velocidad inicial = 25 m/s

Tiempo, t = 7 segundos

Para encontrar la altura (desplazamiento) de la pelota, usaríamos la segunda ecuación de movimiento;

[tex] S = ut + \frac {1}{2}at^{2}[/tex]

Dónde;

S representa el desplazamiento o altura medida en metros.

u representa la velocidad inicial medida en metros por segundo.

t representa el tiempo medido en segundos.

a representa la aceleración medida en metros por segundo cuadrado.

Sustituyendo en la ecuación, tenemos;

[tex] S = 25*7 + \frac {1}{2}*(9.8)*7^{2}[/tex]

[tex] S = 175 + 4.9*49 [/tex]

[tex] S = 175 + 240.1 [/tex]

S = 415.1 meters

An organism with the alleles Aa is called __________, while one with AA or aa is called __________.

A. heterozygous, hom/ zygous
B. heterozygous, homo/zygous

Answers

Answer:

Hetefrozygous, homofzygous

Can someone please help me with this

Answers

Answer:

i dont know about this

Explanation:

Miles Tugo is camping in Glacier Canyon and he makes a loud holler. The sound bounces off the nearest canyon wall (which is located 170 meters away from Miles) and returns to Miles.
Determine the time elapsed between when Miles makes the holler and the echo is heard.

Answers

Answer:

It would take 1 s to hear the echo.

Explanation:

Here, the sound covered a total of 340 meters, since it bounces off the canyon wall and travels back to Miles in the form of echo.

The time elapsed can be determined by,

v = [tex]\frac{2D}{t}[/tex]

⇒ t = [tex]\frac{2D}{v}[/tex]

where: v is the speed of sound in air (343 m/s), D is the distance of the nearest canyon (170 m).

So that,

2D = 2 x 170 = 340 m

Thus,

t = [tex]\frac{340}{343}[/tex]

 = 0.9913 s

t = 1 s

It takes 1s for Miles to hear his echo.

Copper and hydrogen con euch be formed by electrolysis,
At which electrodes are these stoments formed?
copper
hydrogen
A
anode
anode
B
anode
cathode
cathode
anode
D
cathode
cathode
ОА, А

Answers

Answer:

C.cathode, cathode

Explanation:

In electrolysis, a device called ELECTRODE, which electric current passes through is used. However, electrodes can either be anode or cathode depending on the charge. Anode is a positive electrode that attracts negative ions while cathode is a negative electrode that attracts positive ions.

According to this question, Copper (Cu) and hydrogen (H) which are both positive ions i.e. Cu2+ and H+ will move towards and form at the CATHODE. Hence, the answer is cathode, cathode for the respective element.

If a sample of an unknown material with a mass of 0.68 g and a volume of 0.8 cm3 is dropped
into maple syrup, will it sink or float? maple syrup has a density of 1.33 g/cm3

Answers

As the density of the unknown substance is 0.68g/0.8ml = 0.85g/ml, it is less dense than the maple syrup at 1.33g/ml and will float.

how to prevent air resistance or what reduces air resistance?

Answers

Answer:

reducing the area in contact with air and being more streamlined

Explanation:

The amount of air resistance an object experiences depends on its speed, its cross-sectional area, its shape and the density of the air

Pls someone help me!!!!!

Answers

Answer:

Seeing as how the balloon is mainly negatively charged and the paper being positively charged, the answer would be B: The tissue paper will stick to the balloon because the tissue paper is positively charged!

The answer is B. There are more +s than -s on the paper, making the overall charge positive, and more -s than +s on the balloon, making the overall charge negative. Since opposites attract, the correct answer is choice B.


Is 35 miles per hour a vector or a scalar?
1. vector
2. scalar

Answers

Answer:

scalar

is the correct answers

Answer:

Scalar

Explanation:

Mph, cubic feet,pounds, and hours are scalar terms

Pedro picked up and held a cube of ice in his hand and noticed that he no longer felt a difference in temperature after the ice cube melted in his hand. Which of the following statement best explains what happened?
1.Heat was transferred from Pedro’s hand to the ice increasing the temperature of the ice.
2.Heat was released from the ice cube into the air increasing the temperature of the ice.
3.Cold was transferred to Pedro’s hand from the ice increasing the temperature of the ice.
4.Heat was released from Pedro’s hand into the air melting the ice increasing the temperature of the ice.

Answers

Answer:

the answers is 1.

Explanation:

this is because heat always travel's from the warmest object to the coldest. His hands thermal energy is transferred to the ice making the ice round to the same temperature of his hand. This can also be an example of equalibrum.

Approximately what % of the moons surface is illuminatednon a new-moon day?

Answers

Answer: 0%

Explanation: hope this help

A compact car, mass 664 kg, is moving at 19 km/h toward the east. What is the car's momentum in kg x m/s?

Answers

Answer:

3504.4 kgm/s

Explanation:

First, convert km/hr to m/s:

19 km/hr x 1000m/1km x 1/60min x 1/60s = 5.28 m/s

p = mv

p = (664 kg)(5.28 m/s) = 3504.4 kgm/s

what is the mass of modelling clay?​

Answers

the mass of modelling clay is 500g

The modeling clay mass white 500g

what is a benefit of fossil fuel consumption?

Answers

Answer:

increased greenhouse gases

Explanation:

I think this is the right answer...

Which possesses the most gravitational potential energy?

A. a 4 kg object 0.25 m above the ground.
B. a 100 g object 20 m above the ground.
C. a 2kg object 0.75 m above the ground.
D. a 50 g object 30 m above the ground.

Answers

Answer:

uxjdkddoedlkfkkllllllllo

I’m think it’s B or A

The diagram shows the speed-time graph of a car travelling between two sets of traffic lights.
Calculate the distance travelled by the car in the first 5 seconds of its journey.

Answers

Distance = speed x time
= 12 x 5 = 60 m

DO NOW: You are picking up a pendulum (Clay ball on a string) as you pull the pendulum up on one side and let it fall, what types of energy are being used?

Answers

Answer:

The energy used in the pendulum is the initial Potential (Mechanical) Energy, P.E. given to the Clay ball attached to the inclined and extended string by virtue of its elevated position in relation to the rest position (lower state)

The swinging of the pendulum is brought about by the dynamic equilibrium between the initial potential energy, P.E. and the Kinetic Energy, K.E., of the pendulum when it is in motion

The (total) Mechanical Energy, M.E. of the ideal pendulum is constant at all times during the motion of the pendulum and it is given by the following formula;

M.E. = P.E. + K.E.

At the top of the swing, P.E. is maximum and K.E. is zero

Similarly, at the mid (lowest) point in the swing, instantaneously, P.E. is zero and K.E. is maximum

Explanation:

What will most likely happen if a sound wave moves from the air through a solid?
O It will increase in frequency.
O It will decrease in speed.
O It will increase in speed,
O It will decrease in wavelength.​

Answers

The most likely outcome when a sound wave moves from the air through a solid is : ( C ) It will increase in speed

Sound waves

A sound wave is disturbance pattern that goes through a medium such as  air and any liquid or solid medium. when a sound wave moves from air medium through a solid medium the speed at which the sound waves moves will increase due to the change in medium.

Hence we can conclude that the most likely outcome when a sound wave moves from the air through a solid is it will increase in speed.

Learn more about sound waves : https://brainly.com/question/1199084

True or false? Humans use more water for washing at home than for any other use.

Answers

False because The largest use of household water is to flush the toilet, followed by taking showers and baths. Toilets account for nearly 30 percent of an average home's indoor water consumption. Older, inefficient toilets can use as much as three to six gallons per flush.

A .8 kg block is attached to the end of a spring whose spring constant is 85 N/m. The block is placed on a frictionless tabletop, give an initial displacement of 3.5 cm and then released. What is the magnitude of this energy?​

Answers

Answer:

E = 0.052 J

Explanation:

We are given;

Spring constant; k = 85 N/m

Displacement; x = 3.5 cm = 0.035 m

Formula for the energy is;

E = ½kx²

E = ½ × 85 × 0.035²

E = 0.052 J

Why do you think the speed of sound is higher
in solids, than liquids and gases?

Answers

Answer:

Explanation:

Particles of a solid are closely packed, and  when a solid is hit to produce a sound the kinetic energy present in the solid will cause the particles to vibrate vigorously in the intermolecular spaces in the solid, whereas the paticles of liquids and gases are rather further apart therefore having large intermolecular spaces between particles.

PLEASE HELP 20 POINTS

A car of mass 700 kg and moving at a speed of 30 m/s collides with a stationary truck of mass 1400 kg, and the two vehicles lock together on impact. The combined velocity of the car and truck after the collision is m/s.

Answers

Answer:
10m/s
Explanation:
(m1)(v1)+(m2)(v2)= (m1+m2)(v[final])
(700)(30)+(1400)(0)= (700)(v)+(1400)(v)
21000= 2100v
v=10m/s

A tractor pulls a 978 kg wagon at a velocity of 4.9 m/s. How many watts of power are exerted by the tractor motor is the tractor pulls the wagon at a 60 degree angle?

Answers

Answer:

23481.78 W

Explanation:

The computation of number of watts of power is shown below:

M = 978 kg

V = 4.9 m/s

Theeta = 60°

As we know that  

 P = Fcos(theeta).V

F = Mg

P = (Mg)cos(theeta).V

P = 978×9.8×cos(60)×4.9

P = 23481.78 W

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