1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Jobisdone [24]
4 years ago
7

A constant current of I = 15 A exists in a solenoid whose inductance is L = 2.8 H. The current is then reduced to zero in a cert

ain amount of time. (a) If the current goes from 15 to 0 A in a time of 75 ms, what is the emf induced in the solenoid? (b) How much electrical energy is stored in the solenoid? (c) At what rate must the electrical energy be removed from the solenoid when the current is reduced to 0 A in a time of 75 ms? Note that the rate at which energy is removed is the power.
Physics
1 answer:
julia-pushkina [17]4 years ago
7 0

Answer:

Explanation:

Given that

Constant current I=15A

Inductance L=2.8H

a. Current changes from 15A to 0A.

∆I=0-15=-15

For a time of t=75ms=0.075s

EMF=?

EMF is given at

EMF=-L(∆I/t)

EMF=-2.8×-15/0.075

EMF=3.15V

b. Energy stored?

Energy stored is given as

E=½LI²

E=½×2.8×15²

E=315 J

c. Rate of energy? Which is power and the rate of energy is given as

Power=Energy/timetaken

Power=315/0.075

Power=4200W

P=4.2KW

You might be interested in
How does fungi, snails, earthworms, and pill bugs return nutrients to the ecosystem?
luda_lava [24]
They decompose and leave their nutrients in the earth. 
4 0
3 years ago
If the period of a spring is 5 seconds what is the frequency
Scilla [17]

Answer:

C. 0.2 Hertz

Explanation:

The frequency of a spring is equal to the reciprocal of the period:

f=\frac{1}{T}

where

f is the frequency

T is the period

For the spring in this problem,

T = 5 s

therefore, the frequency is

f=\frac{1}{5 s}=0.2 Hz

7 0
3 years ago
Explain the role that the ant and the acacia tree play in their symbiotic relationships
MAXImum [283]
<span>The presence of mutualistic ants greatly reduces bacterial abundance on surfaces of acacia leaves and has a visibly positive effect on plant health</span>
7 0
3 years ago
Which object has a varying speed? a bird flying at 10 m/s for 10 seconds a car slowing from 60 m/s to 0 m/s a car traveling the
dolphi86 [110]

Answer:

The car slowing from 60 m/s to 0 m/s

Explanation:

The bird flying at 10m/s for 10 seconds will have the same speed for those 10 seconds. So we can say it doesn't have a varying speed (During those 10 seconds, we don't have any information about what happens later).

The fish moving at 2m/s for 5 minutes will have the same speed for those 5 minutes. So we can say it doesn't have a varying speed (During those 5 minutes, we don't have any information about what happens later).

The car traveling the speed limit, we know that his speed is the speed limit. It doesn't change.

The car slowing from 60 m/s to 0 m/s needs to change his speed in order to go from 60 m/s to 0 m/s. The speed will decrease progressively until the car completely stops.

8 0
3 years ago
A concave lens has a focal length of -31 {cm}. Find the image distance and magnification that results when an object is placed 2
kolezko [41]

Answer:

The value is v  =  440 \  cm

and  

 m  =  16

Explanation:

From the question we  are told that

    The image  distance is  v  =  29 \  cm

    The focal length is f =  -31 \  cm

From the lens equation we have that

      \frac{1}{f}  =  \frac{1}{v}  - \frac{1}{u}

=>    \frac{1}{-31}  =  \frac{1}{v}  - \frac{1}{29}

=>     v  =  450 \  cm

Generally the magnification  is  

      m  =  \frac{v}{u}

=>    m  =  \frac{ 450}{29}

=>    m  =  16

7 0
3 years ago
Other questions:
  • Which of the following examples describes an increase in potential energy? Please provide answer and explain. I will mark brainl
    8·2 answers
  • On the position-time graph, what is the average velocity between 5 s and 10 s?
    11·1 answer
  • High pitched sounds have relatively large ___ and small ___
    12·1 answer
  • Diesel fuel is used in the engine of trucks that carry dirt fruit and other cargo. Fuel is burned in engines to make the motor m
    14·1 answer
  • A 250 kg flatcar 25 m long is moving with a speed of 3.0 m/s along horizontal frictionless rails. A 61 kg worker starts walking
    8·1 answer
  • Jupiter is 317 times more massive than the Earth. An astronaut on Jupiter would _____. weigh less than on Earth weigh more than
    5·1 answer
  • Which of the following situations reflect the effects of deindividuation?
    10·2 answers
  • You are riding in an elevator that is accelerating upward. Suppose you stand on a scale. The reading on the scale is __________.
    13·2 answers
  • Astronauts on the first trip to Mars take along a pendulum that has a period on earth of 1.26 s. The period on the other planet
    10·1 answer
  • "My distance to the center of the earth is about 4000 miles when I am on the surface. If I go to a height of 8000 miles above th
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!