All categories

3 years ago

Without his glasses, Isaac can see objects clearly only if they are less than 4.7 m from his eyes.

Physics

1 answer:

Mazyrski [523]3 years ago

6 0

Answer:

The focal length is $f = -4.721 \ m$

Explanation:

From the question we are told that

The image distance is $v = 4.7 + (2.1 *10^{-2}) = - 4.721 \ m$ the negative means image is formed behind the lens

Generally the object distance is $u = \infty$ this mean the light ray coming from the object are parallel to each other

So from lens equation

$\frac{1}{\infty } - \frac{1}{4.721} = \frac{1}{f}$

=> $f = -4.721 \ m$

You might be interested in

Based on their locations on the periodic table, which two elements would you

Nat2105 [25]

Answer:

i think it would be B. Aluminum, Al and D. Boron, B

Explanation:

since they're both in group 13 and they forms a 3+ ion

6 0

3 years ago

Read 2 more answers

Which situation describes the highest rate of power?

Darya [45]

Answer : The correct option is, (D) A machine does 400 joules of work in 5 seconds.

Explanation :

Power : It is defined a the rate of doing work per unit time.

Formula used :

$P=\frac{w}{t}$

where,

P = power

w = work done

t = time

Now we have to determine the rate of power for the following options.

(A) A machine does 200 joules of work in 10 seconds.

$P=\frac{200}{10}=20W$

(B) A machine does 400 joules of work in 10 seconds.

$P=\frac{400}{10}=40W$

(C) A machine does 200 joules of work in 5 seconds.

$P=\frac{200}{5}=40W$

(D) A machine does 400 joules of work in 5 seconds.

$P=\frac{400}{5}=80W$

From this we conclude that, a machine does 400 joules of work in 5 seconds has the highest rate of power.

Hence, the correct option is, (D)

8 0

3 years ago

If we think of the value system, as a river, and each stop along the river is a port where value was added. What was the startin

denis23 [38]

Answer:

The raw materials.

Explanation:

The starting point of every manufactured object is the raw material. In the value system of the film industry, the starting point is the raw material which includes chemicals used in the manufacture of films and cameras.

Therefore, If we think of the value system, as a river, and each stop along the river is a port where value was added. The starting point, the furthest upstream, in the value system in the film industry is the raw materials.

6 0

3 years ago

You want to slide a 0.39 kg book across a table. If the coefficient of kinetic friction is .21, what force is required to move t

uranmaximum [27]

Find the force that would be required in the absence of friction first, then calculate the force of friction and add them together. This is done because the friction force is going to have to be compensated for. We will need that much more force than we otherwise would to achieve the desired acceleration:

$F_{NoFric}=ma=0.39kg \times0.18 \frac{m}{s^2} =0.0702N$

The friction force will be given by the normal force times the coefficient of friction. Here the normal force is just its weight, mg

$F_{Fric}=0.39kg \times 9.8 \frac{m}{s^2} \times 0.21=0.803N$

Now the total force required is:

0.0702N+0.803N=0.873N

5 0

3 years ago

Why might a major volcanic eruption lead to cooler global temperatures? Explain your answer.

irina [24]

Answer:

Volcanic eruptions cool down the planet

Explanation:

Volcanic eruptions actually cool the planet because the particles ejected from volcanoes shade incoming solar radiation. ... The small ash and aerosol particles decrease the amount of sunlight reaching the surface of the Earth and lower average global temperatures.

Hope this helps!!! :D

4 0

3 years ago