Ask question

Ask question

All categories

brilliants [131]

1 year ago

15

It is desired to project the image of an object five times it's actual size using a lens of focal length 30 cm how far from the

lens should the object be placed

1 answer:

Maurinko [17]1 year ago

6 0

Answer:

focal length have radian.. sjsbxhxnxnsb

You might be interested in

a high speed train travels with an average speed of 250 km/h. the train travels for 2 hrs. how far does the train travel

steposvetlana [31]

Answer:

<h3>The answer is 500 km </h3>

Explanation:

The distance covered by an object given it's velocity and time taken can be found by using the formula

<h3>distance = average velocity × time</h3>

From the question

average speed = 250 km/h

time = 2 hrs

We have

distance = 250 × 2

We have the final answer as

<h3>500 km</h3>

Hope this helps you

5 0

2 years ago

Read 2 more answers

For heat transfer purposes, an egg can be considered to be a 5.5-cm-diameter sphere having the properties of water. An egg that

Harrizon [31]

Answer:

The time taken is $t = 40007 sec$

Explanation:

From the question we are told that

The diameter of the egg is $d_e = 5.5cm = \frac{5.5}{100} = 5.5*10^{-2}m$

The initial temperature of egg the $T_e = 4.3^{o}C$

The temperature of the boiling water $T_b = 100^oC$

The heat transfer coefficient is $H = 800 W/m^2 \cdot K$

The final temperature is $T_e_f = 74^oC$

The thermal conductivity of water is $k = 0.607 W/m^oC$

The diffusivity of the egg $\alpha = 0.146 * 10^{-6} m^2 /s$

Using one term approximation

We have the

$\frac{T_e_f - T_b}{T_e - T_b} = Ae^{-\lambda ^2 \tau}$

The radius is $r = \frac{5.5*10^ {-2}}{2} =2.75*10^{-2}m$ Note that this radius is approximation to that of a real egg

Now we need to obtain the Biot number which help indicate the value of $A \ and \ \lambda$ to use in the above equation

The Biot number is mathematically represented as

$Bi = \frac{H r}{k}$

Substituting values

$Bi = \frac{800 * 2.75 *10^{-2}}{0.607}$

$= 36.24$

So for this value which greater than 0.1 the coefficient $\lambda_1 \ and \ A_1$ is

$\lambda = 3.06632$

$A = 1.9942$

Substituting this into equation 1 we have

$\frac{74- 100}{4.3 - 100} = 1.9942 e^{-(3.0632^2) \tau}$

$0.2717= 1.9942 e^{-(3.0632^2) \tau}$

$0.2717= 1.9942 e^{-9.383 \tau}$

$0.13624 = e^{-9.383 \tau}$

Taking natural log of both sides

$-1.993 = -9.383\ \tau$

$\tau = 0.2124$

The time required for the egg to be cooked is mathematically represented as

$t = \frac{\tau r^2}{\alpha }$

substituting value is

$= \frac{0.2124 * 2.75 *10^{-2}}{0.146 *10^{-6}}$

$t = 40007 sec$

8 0

3 years ago

Janice has just measured the density of an object. Which value is possible? (Density: D = )

babunello [35]

It is 6 g/cm3 because density cannot be negative, and it is not speed in which the unit would be m/s.

6 0

3 years ago

Read 2 more answers

Freckles are a dominant trait in humans. Both of the girls have the genotype FF for freckles. If either one marries a man with n

trapecia [35]

D. The man's traits (ff) would be recessive and with one of the girls (FF), all their offspring would have the genotype Ff, meaning all the offspring have freckles.

3 0

2 years ago

Read 2 more answers

PLS HELP THIS IS DUE TODAY!!!!!!!!!

Juli2301 [7.4K]

The speed at which the objects were attracted to each other determined by the gravitational pull.

<h3>What is gravity?</h3>

The force of attraction felt by a person at the center of a planet or Earth is called as the gravity or gravitational pull.

The gravitational force, Fg is the attractive force exerted by the Earth on the object that is equal to the mass of the object times the gravitational acceleration.

When the two objects are attracted, the speed with which they are moving toward each other depends on the strength of the pull force. This pull force is the gravitational pull.

Thus, the speed at which the objects were attracted to each other determined by the gravitational pull.

Learn more about gravity.

brainly.com/question/4014727

#SPJ1

3 0

2 years ago