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Stolb23 [73]
3 years ago
11

At what distance will a 80 W lightbulb have the same apparent brightness as a 120 W bulb viewed from a distance of 40 m

Physics
1 answer:
liq [111]3 years ago
4 0

Answer:

32.6mm

Explanation:

Using area of a sphere(bulb) = 4πr²

So A is proportional to radius²

So the Energy will be proportional to r²

But 120/80 = 1.5 is the energy factor so

Using

1.5/d² = 1/r²

1.5/40²= 1/r^2

r = √( 40²/ 1.5)

r = 32.6m

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Bob will not develop a good habit if he _____. works out for only one week develops a consistent schedule of exercise works out
Charra [1.4K]

Answer:

works out for only one week

Explanation:

In order to develop a good habit, there are certain things that you can do like:

-Develop a consistent schedule of exercise which allows you to work everyday over a period of time which helps you to create a routine that you would get used to it creating a habit.

-Work out with a friend which allows you to have someone to motivate you and that would go everyday with you which would help to be consistent.

-Use success strategies that are ways in which you can achieve your goal of creating a good habit to exercise.

According to this, the option that would not help Bob develop a good habit is if he works out for only one week as doing something everyday is what would help you to create the habit.

3 0
3 years ago
PLLSSSS HELP<br> MARKING BRAINLIST<br> SCIENCE
Sveta_85 [38]

Answer:

the first one

Explanation: the first one because they were all on two different continents so when they seperated half of the species went on one continent and the other half went onto another one

3 0
3 years ago
A driver is traveling eastward on a dirt road when she spots a pothole ahead. She slows her car from 14.0 m/s to 5.5 m/s in 6.0
Ivahew [28]

Answer:

- 1.42m/s²

Explanation:

Acceleration is defined as the change in velocity of a body with respect to time.

Acceleration = change in velocity/time

Change in velocity = final velocity - initial velocity

Acceleration = final velocity - initial velocity/time

Since she slows her car from 14.0 to 5.5m/s in 6seconds,

Initial velocity = 14m/s

Final velocity = 5.5m/s

Time = 6seconds

Substituting in the given formula, we will have

Acceleration = 5.5 - 14/6

Acceleration = - 8.5/6

Acceleration = - 1.42m/s²

The negative acceleration shows that the car decelerates.

8 0
3 years ago
Help please what law is happening in these pictures
Karolina [17]
Answer: boyles law I’m pretty sure
7 0
2 years ago
A spiral spring of 8cm extended to 9.2cm when a load of 1.6N is applied. what is the force constant of the spring, provided the
DerKrebs [107]

Explanation:

By Hooke's Law, Fe = kx.

Since Fe = 1.6N and x = 9.2cm - 8cm = 1.2cm,

k = Fe/x = 1.6N/1.2cm = 1.33N/cm.

5 0
2 years ago
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