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3 years ago

Explain why incandescent light bulbs are not energy efficient? Also use the words heat energy, electricity energy, light energy.

1 answer:

3 0

Because incandescent light bulbs emit much, much more heat energy than light energy. So, they convert more of the electric energy put into them into heat energy than light energy. P.S. Learn this stuff yourself. Don't cheat

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Help! Elastic Collision.

chubhunter [2.5K]

If the question is in Mastering physics online, then the answer is not that hard. in fact, it's about the wording...

<span>You have to enter both ratios, meaning, you have to enter 5.83 and it's reciprocal, 0.1715...

I hope my answer has come to your help. Thank you for posting your question here in Brainly. We hope to answer more of your questions and inquiries soon. Have a nice day ahead!

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3 0

4 years ago

An object 2.7 cmtall is placed12 cmin front of a mirror. •What type of mirror and what radius of curvature are needed to createa

nasty-shy [4]

Answer:

a. Concave mirror, radius of curvature = 16 cm b. magnification = 2

Explanation:

a. Since the image is upright and larger than the object, we need a concave mirror.

We know image height, h'/object height, h = -image distance, d'/object distance, d

h'/h = -d'/d

Using the real is positive convention,

h'= + 5.4 cm, h = + 2.7 cm and d = + 12 cm.

So, + 5.4 cm/+ 2.7 cm = -d'/+ 12 cm

2 = -d'/12

d' = -2 × 12 cm

= -24 cm

Using the mirror formula 1/d + 1/d' = 2/r where r = radius of curvature of the mirror

1/+12 + 1/- 24 = 2/r

1/12(1 - 1/2) = 2/r

1/12(1/2) = 2/r

1/24 = 2/r

r/2 = 24

r = 2 × 24

r = 48 cm

magnification = image height, h'/object height,h = + 5.4 cm/+ 2.7 cm = 2

3 0

3 years ago

What is the pressure drop due to the Bernoulli Effect as water goes into a 3.00-cm-diameter nozzle from a 9.00-cm-diameter fire

Marianna [84]

Answer:

The pressure and maximum height are $1.58\times10^{6}\ N/m^2$ and 161.22 m respectively.

Explanation:

Given that,

Diameter = 3.00 cm

Exit diameter = 9.00 cm

Flow = 40.0 L/s²

We need to calculate the pressure

Using Bernoulli effect

$P_{1}+\dfrac{1}{2}\rho v_{1}^2+\rho g h_{1}=P_{2}+\dfrac{1}{2}\rho v_{2}^2+\rho g h_{2}$

When two point are at same height so ,

$P_{1}+\dfrac{1}{2}\rho v_{1}^2=P_{2}+\dfrac{1}{2}\rho v_{2}^2$ ....(I)

Firstly we need to calculate the velocity

Using continuity equation

For input velocity,

$Q=A_{1}v_{1}$

$v_{1}=\dfrac{Q}{A_{1}}$

$v_{1}=\dfrac{40.0\times10^{-3}}{\pi\times(1.5\times10^{-2})^2}$

$v_{1}=56.58\ m/s$

For output velocity,

$v_{2}=\dfrac{40.0\times10^{-3}}{\pi\times(4.5\times10^{-2})^2}$

$v_{2}=6.28\ m/s$

Put the value into the formula

$P_{1}-P_{2}=\dfrac{1}{2}\rho(v_{1}^2-v_{2}^2)$

$\Delta P=\dfrac{1}{2}\times1000\times(56.58^2-6.28^2)$

$\Delta P=1.58\times10^{6}\ N/m^2$

(b). We need to calculate the maximum height

Using formula of height

$\Delta P=\rho g h$

Put the value into the formula

$1.58\times10^{6}=1000\times9.8\times h$

$h=\dfrac{1.58\times10^{6}}{1000\times9.8}$

$h=161.22\ m$

Hence, The pressure and maximum height are $1.58\times10^{6}\ N/m^2$ and 161.22 m respectively.

8 0

4 years ago

1. Differentiate between speed and velocity.

Mazyrski [523]

Answer:

1. Speed and velocity both involve a numeric rate describing the distance traveled by a body in a unit of time. However, speed describes the rate of a body traveling in any direction in a unit of time, while velocity describes the rate of a body traveling in a particular direction in a unit of time.

2. Answers may vary, but should resemble the following:

Average velocity explains the velocity the body traveled overall, not taking into consideration each spot in the trip. If a car moves at 65 km/h on average, it may have slowed down for some parts and sped up for others. Overall though, it would have made a certain distance of travel within a specified unit of time that totals the average velocity of 65 km/h.

Instantaneous velocity explains the velocity of a body at a particular instant of the trip. The instantaneous velocity of a car stopped at a stop sign would be 0 m/s even if it was moving before and will continue to move after this stop. The velocity at that particular instant is the instantaneous velocity.

Uniform velocity is when the distance being covered is changing uniformly with time. For example, if a car moves 20 km every 30 minutes and continues to do so in the same direction, it's traveling with a uniform velocity.

3. a=v2−v1t

a=20 m/s−60 m/s6 s

a=−406

a = –6.7 m/s2

4. v2 = v1 + at

v2 = 14 m/s + (3 m/s2 × 6 s)

v2 = 14 + 18

v2 = 32 m/s

5. v=st

v=375 km5 h

v = 75 km/h

6. First, convert the minutes to seconds. Since there are 60 seconds in one minute, multiply:

60 × 15 (minutes) = 900 seconds

s = v × t

s = 6 m/s × 900 s

s = 5,400 m

7. t=sv

t=80 km35 km/hr

t = 2.29 hr

8. a=v2−v1t

a=50 m/s−15 m/s4 s

a=35 m/s4 s

a = 8.75 m/s2

9. vav=v1+v22

vav=15 m/s+50 m/s2

vav=65 m/s2

vav = 32.5 m/s

10. a=v2−v1t

a=0 m/s−11.5 m/s3.5 s

a = –3.29 m/s2

Explanation:

7 0

3 years ago

The minimum voltage that is required to generate an action potential is called the _______.

allochka39001 [22]

The answer would be threshold voltage. It is the minimum value of voltage needed to produce an action potential. It is also known as gate voltage. It is the minimum value that would make turn a transistor on. Hope this answers the question.

3 0

3 years ago