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
lara31 [8.8K]
3 years ago
15

PLEASE ANSWER, 75 PTS, AND BRANLIEST!

Physics
1 answer:
n200080 [17]3 years ago
7 0

Answer:

An electromagnet is a device which moving electric charges(current) in a coil of wire create a magnet. Electromagnets can easily be turned off and on because it is a electromagnet. When current flows through a wire, a magnetic field is produced around a wire and create an electromagnet. The coils are always made of copper wire because copper is a good conductor of electricity.

Explanation:

You might be interested in
What is happening to the energy in the ice and snow as it is melting?
klio [65]
Answer:
all the heat energy goes into breaking the bonds of the ice's crystal lattice structure.


Explanation:
When you heat ice, its temperature rises, but as soon as the ice starts to melt, the temperature stays constant until all the ice has melted.
7 0
3 years ago
I would appreciate some help.
motikmotik
You oughtta be able to do this one.

The "efficiency" is just the portion of the input work that
comes out in a useful form.

If the efficiency is 70%, that tells you that however much work
you put INto the machine, the machine will do 70% of that much
work for you at the output side.

Put 20,000 J in ... out comes (0.70) x (20,000 J)  =  14,000 J .

What happens to the other 30% of the work you put into it ?
It turns into HEAT.  That's why machines always have to be
cooled somehow while they're running.  
 
4 0
3 years ago
Two billiard balls of identical mass move toward each other. Assume that the collision between them is perfectly elastic. If the
anzhelika [568]

Answer:

-20.0 m/s and 30.0 m/s

Explanation:

Momentum is conserved:

m (30.0) + m (-20.0) = m v₁ + m v₂

30.0 − 20.0 = v₁ + v₂

10.0 = v₁ + v₂

Since the collision is perfectly elastic, energy is also conserved.  Since there's no rotational energy or work done by friction, the initial kinetic energy equals the final kinetic energy.

½ m (30.0)² + ½ m (-20.0)² = ½ mv₁² + ½ mv₂²

(30.0)² + (-20.0)² = v₁² + v₂²

1300 = v₁² + v₂²

We now have two equations and two variables.  Solve the system of equations using substitution:

1300 = v₁² + (10 − v₁)²

1300 = v₁² + 100 − 20v₁ + v₁²

0 = 2v₁² − 20v₁ − 1200

0 = v₁² − 10v₁ − 600

0 = (v₁ + 20) (v₁ − 30)

v₁ = -20, 30

If v₁ = -20, v₂ = 30.

If v₁ = 30, v₂ = -20.

So either way, the final velocities are -20.0 m/s and 30.0 m/s.

3 0
3 years ago
Read 2 more answers
Which of the following is not a lever?<br>a. winch<br>b. scissors<br>c. can openers<br>d. tweezers​
LekaFEV [45]

Answer:

a?

Explanation:yes it is a

4 0
2 years ago
Read 2 more answers
Which is more dangerous to living things: gamma rays or X-rays?
Dima020 [189]

Answer:

gamma

Explanation:

x rays are often used in hospitals

gamma rays :

are highly penetrating

have highly energetic ionizing radiation

frequency is higher

wavelengths are shorter rays

can attack DNA and break the strands of that essential biological molecule

quizlet

brainly.com/question/13047731

quora

6 0
2 years ago
Read 2 more answers
Other questions:
  • Why the formation of sand is a physical change.
    14·1 answer
  • You are throwing a stone straight-up in the absence of air friction. If the stone is caught at the same height it was thrown fro
    6·1 answer
  • Which example involves the transformation of chemical energy directly into light energy?
    12·2 answers
  • About 3% of the water on Earth is freshwater. Only about 40% of that freshwater is available for human use. Why is so much fresh
    5·2 answers
  • The Sun appears at an angle of 48.4° above the horizontal as viewed by a dolphin swimming underwater. What angle does the sunlig
    8·1 answer
  • Charge A and charge B are 3.00 m apart, and charge A is +1.44 C and charge B is +3.10 C. Charge C is located between them at a c
    12·1 answer
  • A standing wave is one which travels through space indefinitely. true or false?
    9·2 answers
  • What is acceleration, and what units do we use to measure it? *
    13·1 answer
  • What quantities belong in cells X and Y?
    11·1 answer
  • Martin perceived that there was music playing. Martin
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!