Sometimes on a sunny day campers start a campfire using a small mirror to light paper or dry grass. What shape of mirror would you use for this purpose? Explain your choice using reasoning.
Answer: concave mirror
Explanation: There are different types of mirror. Plain, concave and convex mirror to mention a few. Among the mirrors mentioned above, concave mirror has highest focal point. The ability to focus all the beam of light incident on it at a point which can ignite a fire.
Using a small mirror to light paper or dry grass, the shape of mirror to use for this purpose is therefore a concave mirror.
WILL GIVE BRAINIEST AWARD TO CORRECT
Explain why gamma rays are the most dangerous of all electromagnetic waves.
Answer:
The extremely high energy of gamma rays allows them to penetrate just about anything. They can even pass through bones and teeth. This makes gamma rays very dangerous. They can destroy living cells, produce gene mutations, and cause cancer
The presence of electrons in a substance makes it a conductor of electricity.
True
False
Answer:
False
Explanation:
Just finished the exam
The presence of 'free electrons' in a substance makes it a conductor of electricity. So, the statement is false.
What is meant by a conductor ?The objects or substances that let the flow of electricity through them are known as conductors. The ability to carry heat is another benefit of conductors.
Here,
Since, every electron in an atom carries a negative charge, they can serve as our charge carriers. We can produce electricity if we can compel an electron to move by releasing it from its atom.
Current flowing through the conductors is caused by the free electrons present in them.
Free electrons are valence shell electrons with a weaker nucleus-electron interaction; as a result, they are free to travel in the metal, which acts as a conductor, and carry out current flow.
Hence,
The presence of 'free electrons' in a substance makes it a conductor of electricity. So, the statement is false.
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Lenses work using the _____
of light.
A) emission
B) reflection
C) refraction
D) absorption
70 POINTS HELP PHYSICS THE PICTURE HAS THE QUESTION AND POSSIBLE CHOICES
Answer:
0.3 m/s
Explanation:
0.5 - 0.2 = .3
If you are swimming upstream (i.e., against the current), at what speed does your friend on the shore see you moving?
An important step toward a more complete understanding of blackbody
radiation occurred when Max Planck developed a theory that presented which
of the following ideas?
A. Light is composed of discrete chunks that must be absorbed as a
unit.
B. Large objects can be viewed as acting as waves.
C. Electrons can act as both waves and particles.
D. Matter is composed of discrete chunks that cannot be broken
down.
Answer:
The correct option is;
C. Electrons can act as both waves and particles
Explanation:
The quantum theory theory developed by Max Planck established that effect of radiation on a blackbody can be explained by the fact that energy can exhibit physical characteristics which implies that energy can have both wave-like and physical characteristics
With Planck's law, light and electrons are known as having wave particle duality, that is they can act as both waves and particles.
Answer:
The answer is A. Light is composed of discrete chunks that must be absorbed as a unit.
Explanation:
Hope this helps.
A chemical __ _ is a written method of representing the
changes that occur in a chemical reaction.
Answer:
chemical equation
Explanation:
The general form of a chemical equation is: Reactants → Products. The reactants in a chemical equation are the substances that begin the reaction, and the products are the substances that are produced in the reaction
How have scientists played an important role in history?
A. Scientists control most governments in the world.
B. Scientific discoveries have changed the world.
C. Most political decisions are made by scientists.
D. Historians are mostly scientists.
Answer:
B
Explanation:
B makes the most sense in my opinion. because different discoveries have influenced many factors of the world
Answer: B.
Explanation:
A scientific discovery that has changed the world is Edward Jenner’s vaccine against the smallpox. His vaccine has been further modified to combat other diseases.
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Order the steps to describe how information is sent. A signal is produced. A signal is seen, heard, or used. Radio waves are modulated and amplified. Radio waves are amplified and demodulated.
Answer:
A signal is produced.
Radio waves are modulated and amplified.
Radio waves are amplified and demodulated.
A signal is seen, heard, or used.
Explanation:
Communication is the method of transmitting information between two or more participants. A radio communication network is a set of static and wireless radio equipment developed to facilitate an entity by enabling particular modes of communication such as one-to-many and one-to-one communication. Radio waves are being used to transmit information spatially from the sender to receiver, by modulating the radio signal in the transmitter. The above steps explains the loop of the radio communication system.
Answer:
A signal is produced- 1
A signal is seen, heard, or used- 4
Radio waves are modulated and amplified- 2
Radio waves are amplified and demodulated- 3
Explanation:
got is correct on edge 2020
NEED HELP ASAP!!!!!!!!!!!!!!!!1
Tricep extensions work which of the following muscles:
Biceps
Soleus
Triceps
all of the above
Answer: Its biceps
Explanation: the extension of the triceps are the biceps.
A 1,500 kg car hits a boulder with a force of 500 N, and the collision takes 0.5
seconds. What is the magnitude of its impulse?
A. 75,000 kg-m/s
B. 50 kg-m/s
C. 250 kg-m/s
D. 750 kg-m/s
Answer: C.
250 kg-m/s
Explanation:
Given that the
Mass M = 1,500 kg
Force F = 500 N
Time t = 0.5 seconds
From Newton's second law of motion which state that the rate of change of momentum is proportional to the applied force.
F = mV/t
Ft = mV
Where ft = impulse: the product of time and applied force
Substitutes force and time into the formula
Ft = 500 × 0.5 = 250 Ns
Answer:
c
Explanation:
just took the quiz
What is the total resistance of five 10 ohms resistors in life parallel... a)500 ohms
B)2 ohms
C)10 ohms
D)50 ohms?
Answer: B
R = 2 ohms
Explanation:
When resistors are connected in parallel, the equivalent resistance R will be less than the least resistance.
1/R = 1/R1 + 1/R2 + 1/R3 + 1/R4 + 1/R5
Since the 5 resistors are 10 ohms each, substitute them in to the formula
1/R = 1/10 + 1/10 +1/10 + 1/10 + 1/10
The LCM = 10
1/R = 5/10
Reciprocate both sides
R = 10/5 = 2 ohms
The correct option is B
How can I makeup a physics scenario that includes concepts of work and energy. Should I make something going up or down a ramp!? JUST a SCENARIO plss!!!I'm stressed! I need to be able to make a solution for this made up scenario that includes work and energy calculations.
Answer: Work done = 100Nm
Potential energy = 250 J
Find the remaining solution in the explanation
Explanation:
A person carrying a heavy weight of load without moving does no work. But the load will surely experience potential energy.
Work will be done when he or she covers a little distance.
If the weight of the load = 25 N and the distance covered is 4 metres, the workdone will be the product of the weight and distance covered. That is,
WD = F × d
WD = 25 × 4 = 100Nm
Let assume that the height of the man is 10 m tall.
The load will be experiencing potential energy of mgh. That is,
P.E = mgh
Since weight W = mg
Substitute weight and height into the formula
P.E = 25 × 10 = 250J
A dog walks Along the ground. If the dog applies an action force on the ground, what is the reaction force?
Answer: The answer is weight.
Explanation:
where was forensic science first used to solve a crime?
Answer:
In 1836, Scottish chemist, James Marsh, did the first application of this forensic science technique. This test was actually used successfully in a murder trial at that time.
Explanation:
I hope that is what you were asking
Answer: London , United Kingdom
Explanation:
In 1836, Scottish chemist, James Marsh, did the first application of this forensic science technique.
what’s the difference between gravitational force & gravitational field strength?
Answer:
Gravitational field strength is the force experienced by a unit mass. Gravitational force is the amount of force acting on a body. It is the product of field strength times the mass under consideration. Gravitational pull is just a more colloquial name for gravitational force.
Explanation:
hope it helps u
what’s the difference between gravitational force & gravitational field strength?
What must a magnet always have?
A. Two like poles
B. Two opposite charges
C. Two like charges
D. Two opposite poles
Answer:
the anwser is d
Explanation:
you must have a north and south pole
Answer:
your anwser would be
D) two opposite poles
What is the actual depth of rainfall shown in this rain gauge?
A.20 cm
B.30 cm
C.1 cm
D.10 cm
Answer:
The answer is D.
Explanation:
As shown in the picture, the measuring tube is collecting 10 cm of rain.
Answer:
D. 10cm
Explanation:
If you look closely, you can see the water is at the 10cm mark.
Which has more momentum: a 30 kg bicycle moving at 10 m/s or a 300 kg car at rest?
A bicycle
B car
c they have the same momentum
Momentum = mass × velocity
Case IMomentum of bicycle = 30 × 10 = 300 kgms¯¹
Case IIMomentum of car = 300 × 0 = 0 kgms¯¹
Therefore, 300 > 0 so momentum of bicycle is more. Hence, option A is correct.A 6 kg table has a net force of 15 N acting on it. What is the magnitude of the acceleration of the table?
Answer:
2.5m/s2
Explanation:
F=ma
a=F/m
a=15/6
a=2.5m/s2
What two charges could increase electrical force between objects
Answer:
From Coulomb’s Law of electrostatics the force of attraction or repulsion between two charged bodies is inversely proportional to the square of the distance between their two centers.
If the distance between them is doubled then the force is one-fourth of the original force.
If the distance between them is halved then the force is four times than the original force.
Explanation:
Cicadas produce a sound that has a frequency of 123Hz. What is the wavelength of this sound in air at room temperature? (2.79m)
Answer:
2.72 m
Explanation:
Sound travels at a certain speed and has a frequency and wavelength. The relationship between the speed of sound (V), its frequency (f), and wavelength (λ) is the same as for all waves, it is given by the equation:
V = fλ
The speed of sound in air (V) is 334 m/s
Frequency of sound (f) = 123 Hz
Wavelength = λ
V = fλ
λ = V/f = 334/123
λ = 2.72 m
Jerimiah is studying Wave A and Wave B. Wave A is traveling at 3 hertz, and Wave B is traveling at 1.2 hertz.
What can be predicted about the waves if they were to crash into each other?
A) Refraction would occur
B)Interference would occur
C) the resulting wave would travel at 4.2 hertz
D) the crest of wave A would overlap the trough of wave B
Please hurry
6-4-2020
Answer: the answer is B
Explanation:
Answer:
The resulting wave would travel at 4.2 hertz.
Explanation:
What must be the initial velocity of a rocket that accelerates for 10.2 seconds at 5.31 m/s2 and covers 3912 m?
A. 276 m
B. 356 m/s
C. 107 m/s
D. 384 m/s
Answer: B
Explanation: 3912=10.2v +1/2(5.31)(10.2)^2 -> v≈ 356.45 (B)
what is the frequency of a ocean wave that is traveling at a speed of 45 m/s if it has a wavelength of 3 meters? please show work
Answer:
15 miles per hour
Explanation:
45/3=15
Answer:
15 Hz or Hertz
Explanation:
To find the frequency of a wave, divide the velocity by the wavelength.
f=velocity/wavelength
We know the ocean wave is traveling at 45 meters per second, and it has a wavelength of 3 meters. Therefore, the velocity is 45 m/s and the wavelength is 3 m.
velocity=45
wavelength=3
Substitute these values into the formula.
f=45/3
Divide 45 by 3
f=15
Add appropriate units. Frequency uses Hertz or Hz.
f=15 Hertz
The frequency of the ocean wave is 15 Hertz.
A loop of wire is placed into a magnetic field between two magnets. Since this is a three dimensional, a dashed line is drawn through the loop to show the imaginary slice we take that allows us to picture the electron current flow from different perspectives. How do you think the loop will move? Describe this from the front view perspective
a) clockwise
b) counter-clockwise
c) up
d) down
Answer: the loop will move up
Explanation:
Whenever an electric current cuts across magnetic field lines, a force is exerted on the current - carrying conductor
According to Fleming's left hand rule, the thumb is the direction of motion.
First finger is the direction of magnetic field, while the second finger is the direction of the conventional current.
When a current flow in the will, the wire will experience an upward force. And continue to rotate in an up - down direction. Therefore, the loop will move up.
A particular planet has a moment of inertia of 8.26 × 10^(36) kg⋅m^2 and a mass of 6.54 × 10^22 kg. Based on these values, what is the planet's radius? Hint: Because planets are the shape of a sphere, the moment of inertia is I = (2/5)mr^2.
Answer: 1.776933x10^7
Explanation:
Moment of inertia I = 8.26x10^36kgm^2
Mass of planet m = 6.54x10^22kg
Also, Planet is solid sphere so that, Moment of inertia is I = _2_ m
R^2= 0.4 R^2 5
Where R is radius of planet
Putting into calculation
We get,
I = _2_ m R^2
5
8.26x10^36 = 0.4x6.54x10^22xR^2
8.26x10^14 = 2.616 R^2
R = 1.776933x10^7
The radius of the planet which has a mass of 6.54× 10²² kg and inertia of 8.26 × 10³⁶ kg/m² is 1.776933 × 10⁷.
What is Moment of Inertia?Moment of inertia is a quantitative measure of the rotational inertia of a body. It is the opposition which the body exhibits to having its speed of rotation about an axis altered by the application of a torque.
Moment of inertia I = 8.26 × 10³⁶ kg
Mass of planet m = 6.54× 10²² kg
Also, Planet is solid sphere so that, Moment of inertia is I = 2/5 m R² = 0.4 mR²
where, R is radius of planet
Putting into calculation
We get,
I = 2/5 m R²
8.26 × 10³⁶ = 0.4 × 6.54 × 10²² × R²
8.26 × 10¹⁴ = 2.616 R²
3.15749235 × 10¹⁴ = R²
R = 1.776933 × 10⁷
Thus, the radius of the planet is 1.776933 × 10⁷.
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What is the electric potential 20.0 cm from a negative point charge of 15 µC?
Answer: V = 675000v
Explanation:
Electric potential V can be calculated by using the formula
V = Kq/r
Where
V = electric potential
q = charge = 15µC
K = Coulomb constant = 9 × 10^9Nm^2C^-2
r = 20 cm
Substitute all the parameters into the formula
V = (9×10^9 × 15×10^-6)/20×10^-2
V = 135000/0.2
V = 675000 volt
Psychological researchers study genetics in order to better understand the
that contributes to certain behaviors.
D
biology
neurology
O psychology
physiology
Answer: A
Biology
Explanation:
Psychological researchers study genetics in order to better understand the biological factors that contribute to certain human behaviour.
Because bodies with a particular genetic code are related in some certain behavioral forms and actions such as thought, feelings, attitude e.t.c