Explanation:
Electromagnetic waves are different from sound or water waves in such a way that water and sound waves are called mechanical waves that requires a material medium for their propagation.
Electromagnetic waves do no require a material medium for propagation.
Electromagnetic waves are carried or transported by radiation and this can be passed through vacuums and different other materials. But mechanical waves such as water and sound waves requires a material medium for their propagation. They cannot pass through a vacuum.Why should a person warm up before physical activity?
Answer:
don't wanna pull anything
Explanation:
A good warm-up before a workout dilates your blood vessels, ensuring that your muscles are well supplied with oxygen. It also raises your muscles' temperature for optimal flexibility and efficiency. By slowly raising your heart rate, the warm-up also helps minimize stress on your heart.
Answer:
Here you go!
Explanation:
A good warm-up before a workout dilates your blood vessels, ensuring that your muscles are well supplied with oxygen. It also raises your muscles' temperature for optimal flexibility and efficiency. By slowly raising your heart rate, the warm-up also helps minimize stress on your heart. “Stretching allows for greater range of motion and eases the stress on the joints and tendons, which could potentially prevent injury. Warming up, such as low-heart rate cardio, prepares the circulatory and respiratory system for the upcoming ‘age- and type-appropriate target heart rate’ exercising, whether it’s endurance or sprint type of activities.” The cool-down is just as critical. It keeps the blood flowing throughout the body. Stopping suddenly can cause light-headedness because your heart rate and blood pressure drop rapidly. Before you exercise, think about warming up your muscles like you would warm up your car. It increases the temperature and flexibility of your muscles, and helps you be more efficient and safer during your workout. A warm-up before moderate- or vigorous-intensity aerobic activity allows a gradual increase in heart rate and breathing at the start of the activity.
Tips:
*Warm up for 5 to 10 minutes. The more intense the activity, the longer the warm-up.
*Do whatever activity you plan on doing (running, walking, cycling, etc.) at a slower pace (jog, walk slowly).
*Use your entire body. For many people, walking on a treadmill and doing some modified bent-knee push-ups will suffice.
Which of the following describes a displacement vs. time graph that looks like this?
A)Increasing Velocity
B)Constant Velocity
C)Constant Non-Zero Acceleration
D)Decreasing Acceleration
constant non zero acceleration
THANK YOU SO MUCH PICTURE IS BELOW
Answer:”a” or “d”
Explanation:
I say it will not move because they are moving the objects in the same equal of force so it will most likely stay motionless or might rotate toward the two of the students according to the amount of force they are using
How many moles of water are in 1.5x10^23 molecules of water ?
Answer:
A mole of carbon-12 atoms has 6.022 x 1023 carbon-12 atoms. A mole of apples has 6.022 x 1023 apples.
Explanation:
Why do a hammer and a feather fall at the same rate on the moon but not on the earth?
Answer:
it is because of the differences in medium.
Explanation:
on the moon the medium is in a vaccum. there is no air resistance. therefore they fall at the same time.
Ava lives in Miami, and after a hurricane passed over the city, heavy rains developed and Miami flooded. Why are floods so
destructive?
a. they cause water to remain for a long time because the ground is saturated and it doesn’t run off quickly.
b. flood waters remain for a short time and can happen with very little warning.
c. floods often drain surrounding areas and can bring more flooding.
d. flooding often occurs at night and the flood waters can’t be seen.
the weight of a piece of stone when fully immersed in water is 18N and it displaces 4N of water. what is the weight of the stone in air?
Answer:
4N
Explanation:
Given parameters:
Weight of stone when immersed in water = 18N
Weight of water displaced = 4N
Unknown:
Weight of the stone in air = ?
Solution:
To solve this problem, we employ the Archimedes' principles.
It states that the upward buoyant force on a body is equal to the weight of the fluid displaced.
The weight of the water displaced is equal to the weight of the body.
So, the weight of the stone in air = 4N
Help me with this homework
Answer:
4. The reading decreases because part of your weight is applied to the table and the table exerts a matching force on you that acts in the direction opposite to your weight.
Explanation:
When you push on anything, Newtons Third Law comes into effect: "when two objects interact, they apply forces to each other of equal magnitude and opposite direction." So pretty much, the table you are putting some of your weight on is taking some of the downward force and in return the scale isn't going to push up with as much force.
I'm not the best at explaining, but im in physics right now and thats somewhat how my teacher explained it.
Which action is not an example of work?
picking up a box off the floor
pushing a box across the floor
holding a tray in the cafeteria line
raising a barbell over your head
Answer:
option 3
Explanation:
work is said to be the ability to move an object from it initial position. therefore, holding a tray is not a work
Answer:
C
Explanation:
Hydrometer is a devise used to measure the volume of a liquid. *
True
False
Answer:
false
Explanation:
Hardness, texture, color, and freezing point are all examples of what type of properties of matter?
A.) chemical
B.) positive
C.) physical
D.) negative
Answer:
physical
Explanation:
What is its rotational inertia about the meter stick in the
previous question if it is swung in a circle about one of its
ends?
STICK ABOUT
END
I= '3 mL?
Answer:
Honestly I cant understand that so please explain it someone
Explanation:
Density of water 1000kgper m^3 What will be the volume of 3500
kg water
Answer:
The volume of water is 3.5 cubic meter
Explanation:
Density
The density of a substance or material is the mass per unit volume. The density varies with temperature and pressure.
The formula to calculate the density of a substance of mass (m) and volume (V) is:
[tex]\displaystyle \rho=\frac{m}{V}[/tex]
We are given the density of water as [tex]\rho=1,000\ kg/m^3[/tex].It's required to find the volume of m=3,500 kg of water. Solving for V:
[tex]\displaystyle V=\frac{m}{\rho}[/tex]
[tex]\displaystyle V=\frac{3,500}{1,000}[/tex]
[tex]V=3.5\ m^3[/tex]
The volume of water is 3.5 cubic meter
Name the two poles of a magnet
What is meant by magnetism?
Is this statement true or false?
There are SEVEN days between a NEW MOON and a FIRST QUARTER MOON.
If its false than how many days are between a new moon and a first quarter moon?
Answer:True
Explanation:there are approximately 29.531 on the new moon and and 7.31 I think for the first quarter then it’s 7 days between them if u calculate their sped that light travels and that number it might be the same but the statement is true not false
Answer:
The full cycle of moon phases averages 29.531 days. A quarter of that is 7.38 days. So "7 days" is a pretty good approximation for casual conversation. It's true.
Explanation:
uh i think that was my explanation soooooo like yall have a good day and if you are working at 1am just know it is not gonna be so hard one day it is gonna get better hehe
4. Lead has a density of 11.5g/cm3. A rectangular block of lead measures 7cm ×5cm×2cm.
a) Find the volume of the block of lead.
b) Find the mass of the block of lead
Answer:
a.) volume = 70cm^3
b.) mass = 805 grams
Explanation:
see the explanation in attachment.
Marcus was asked to find out what affects the strength of electromagnets. He was given a simple electromagnet made from a coil of wire and a power supply.
What variables could Marcus investigate?
current passing through wire
number os turns on core
the nature of the core material
the shape and size of the core or the material
In incline plane makes an angle of 40° with the horizontal a body weighing 4000 N initial at rest moves down the slope calculate the distance travelled by the body in 5 seconds if the force of friction is 1500N
Answer:
45.375m
Explanation:
To get the distance travelled by the body we will use the equation of motion
S = ut + 1/2at²
u is the initial speed = 0m/s
a is the acceleration
t is the time = 5 seconds
We need to get the acceleration first:
According to Newton's second law,
[tex]\sum F_x = ma\\F_m - F_f = ma\\[/tex]
Fm is the moving force = Wsin theta
Ff is the frictional force = 1500N
m is the mass = W/g
m = 4000/9.8
m = 408.16kg
Substitute the given values in the formula and get the acceleration:
[tex]Wsin \theta - F_f = ma\\4000sin40^0 - 1500 = 408.16a\\2,980.45 - 1500 = 408.16a\\1,480.45 = 408.16a\\a = \frac{1,480.45}{408.16} \\a = 3.63m/s^2[/tex]
Get the required distance:
Recall that S = ut+1/2at²
S = 0(5) + 1/2*3.63*5²
S = 0+0.5*3.63*25
S = 45.375m
Hence the distance travelled by the body in 5 seconds if the force of friction is 1500N is 45.375m
What is the difference in
momentum between an 87.2 kg
football player running 2.87 m/s and
a 0.0520 kg bullet moving 789 m/s?
209.236 kg · m/s
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightPhysics
Momentum
Momentum Formula: P = mv
P is momentum (in kg · m/s)m is mass (in kg)v is velocity (in m/s)Explanation:Step 1: Define
m₁ = 87.2 kg
v₁ = 2.87 m/s
m₂ = 0.0520 kg
v₂ = 789 m/s
Step 2: Find Momentums
Football Player
Substitute [MF]: P = (87.2 kg)(2.87 m/s)Multiply: P = 250.264 kg · m/sBullet
Substitute [MF]: P = (0.0520 kg)(789 m/s)Multiply: P = 41.028 kg · m/sStep 3: Find difference
Define equation: P₁ - P₂Substitute: 250.264 kg · m/s - 41.028 kg · m/sSubtract: 209.236 kg · m/sAnswer:
209.236
Explanation:
Order of Operations: PEMDAS
"Please excuse my dear Aunt Sally"
Parentheses, exponents, multiplication, division, addition and subtraction
First use p=mv
Player:(plug in the data)
= 87.2*2.87
= 250.264
Bullet : (do the same)
Then subtract Bullet-Player =209.236
If the distance between two objects is increased by a factor of 3 (tripled), how will this affect Fg?
1. F g increases by 9 times
2. F g decreases to 1/9
3. F g increases by 3 times
4. F g decreases to 1/3
Answer:
2. F g decreases to 1/9
Explanation:
The formula for calculating the Force of gravity between two masses separated by a distance is expressed as;
F = GMm/d² ... 1
If the distance is tripled, the new force will be;
F1 = GMm/(3d)²
F1 = GMm/9d² ... 2
Divide equation 1 by 2
F/F1 = GMm/d²÷GMm/9d²
F/F1 = GMm/d²×9d²/GMm
F/F1 = 1 * 9
F = 9F1
F1 = 1/9 F
This means that the new force decreases to 1/9
write the name of two substance used to laminate the core of transformer
Answer:
Transformers use “electrical steel” alloys. ... From 1% to 6.5% silicon is added, as well as a small amount (up to 0.5%) of manganese and aluminum to reduce brittleness in alloys with higher percentages of silicon. Electrical steels are formulated and processed to have low hysteresis and eddy-current losses.
Explanation:
The eddy currents consume energy and heat the iron core. The designers of the electrical machines and transformers laminate the core with thin sheets of iron coated with a thin oxide layer.
To reduce Eddy current loss in the transformer, the iron core is constructed of laminated silicon steel and has a unique insulated coating.
What is used to laminate the core of a transformer?Instead of employing a solid iron block, this can be accomplished by laminating the core, which is constructed from a collection of metal plates that are adhered together.
With less current flow, efficiency loss, and heat waste, this has the desired effect of raising electrical resistance inside the core. Low hysteresis and eddy-current losses are achieved by the formulation and processing of electrical steels.
The iron core is heated by the eddy currents, which use energy. The core of electrical devices and transformers is laminated with thin sheets of iron covered in a thin oxide layer by the designers.
Therefore, Transformers use alloys known as “electrical steel.” To lessen brittleness in alloys with larger percentages of silicon, between 1% and 6.5% silicon is added, along with a tiny amount (up to 0.5%) of manganese and aluminum.
Learn more about core here:
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If a crane lifts a load of 75N to a height of 20m in 100s, what is the power of the crane?
Answer:
P = 15 [W]
Explanation:
Power is defined as the relationship between work over a certain time.
In this way we must calculate the work which is defined as the product of force by distance.
[tex]W=F*d\\W=75*20\\W=1500[J][/tex]
And the power.
[tex]P=W/t\\P=1500/100\\P=15[W][/tex]
Power given in units of watts.
what is wave interactions?
Answer:
Waves interact with matter in several ways. The interactions occur when waves pass from one medium to another. The types of interactions are reflection, refraction, and diffraction. Each type of interaction is described in detail below.
A 30 kg dog runs at a speed of 15 m/s. What is the dog's kinetic energy (in jewels)? Round the answer to two significant digits.
Answer:
K.E = 3400 Joules.
Explanation:
Given the following data;
Mass = 30kg
Velocity = 15m/s
To find the kinetic energy;
Kinetic energy can be defined as an energy possessed by an object or body due to its motion.
Mathematically, kinetic energy is given by the formula;
[tex] K.E = \frac{1}{2}MV^{2}[/tex]
Where, K.E represents kinetic energy measured in Joules.
M represents mass measured in kilograms.
V represents velocity measured in metres per seconds square.
Substituting into the equation, we have;
[tex] K.E = \frac{1}{2}*30*15^{2}[/tex]
[tex] K.E = 15*225 [/tex]
K.E = 3375 Joules.
To two (2) significant digits, the kinetic energy of the dog is 3400 Joules.
Read the selection from the section "Cells Carry Information To The Next Generation."
In the 1880s, Walter Sutton and Theodor Boveri identified the chromosome as being responsible for passing down genes from one generation to the next. The discovery forever linked genetics and cytology. Later discoveries further confirmed and solidified the role of the cell in passing characteristics down from one generation to another. One famous example is James Watson and Francis Crick's studies on the structure of DNA. What conclusion is BEST supported by the selection above?
A) Scientists needed much better microscopes in order to discover how genes and cells are related.
B) Scientists needed to find out how cells performed in order to fully understand genetics.
C) Scientists in the 1880s made the most important discoveries in cell research in modern history.
D) Scientists in the 1880s completely reversed all previous understandings about genetics.
The best conclusion that can be arrived at from the passage is that; "Scientists in the 1880s made the most important discoveries in cell research in modern history."
The cell is the smallest unit of an organism that has independent existence. Genetics has to do with the study of the patterns of inheritance in organisms. The scientific research in the 1880s laid a firm foundation for genetics.
Hence, the conclusion that is best supported by the text is that; "Scientists in the 1880s made the most important discoveries in cell research in modern history."
Learn more about genetics: https://brainly.com/question/12985618
HELP!!
8. The speed that the car is going at an instant of time is called the (5 points)
average speed
final speed
initial speed
instantaneous speed
Answer:
the speed that the car is going at an instant of time is called the instantaneous speed.
a meteroid is in a circular orbit 600 km above the surface of a distant planet. the planet has the same mass as Earth but has a radius that is 90% of Earths (where Earths radius is approximately 6370 km).
The acceleration of the meteroid due to the gravitational force exerted by the planet is most nearly
A) 9 m/s^2 toward the center of the planet
B) 9 m/s^2 in the direction of the meteoroids motion
C) 10 m/s^2 toward the center of the planet
D) 10 m/s^2 in the direction of the meteoroids motion
Answer:
C) 10 m/s^2 toward the center of the planet
Explanation:
g = GM/r^2
The masses of earth and this planet are the same and the radius is only diffferent by 10% so as gravitational force acceleration is 9.8m/s^2 on earth, it can be estimated to be around 10m/s^2.
Using the third law, we know acceleration is toward the larger mass from attraction, thus having it point toward the center of the planet.
A Go Kart (m = 35 kg) has a top speed of 12 m/s . A student traveling at top speed locks the brake to avoid hitting a bus after school, skidding 7.2 meters before stopping. How much force did the Go Kart have when the student locked the brake?
Answer:
350 N
Explanation:
From the question given above, the following data were obtained:
Mass (m) of Go Kart = 35 kg
Initial velocity (u) = 12 m/s
Distance (s) = 7.2 m
Force (F) =?
Next, we shall determine the acceleration of the Go Kart. This can be obtained as follow:
Initial velocity (u) = 12 m/s
Distance (s) = 7.2 m
Final velocity (v) = 0 m/s
Acceleration (a) =.?
v² = u² + 2as
0² = 12² + (2 × a × 7.2)
0 = 144 + 14.4a
Collect like terms
0 – 144 = 14.4a
– 144 = 14.4a
Divide both side by 14.4
a = – 144 / 14.4
a = – 10 m/s²
The negative sign indicate that the Go Kart is decelerating when the brake was applied.
Finally, we shall determine the force the Go Kart have when the student locked the brake. This can be obtained as follow:
Mass (m) of Go Kart = 35 kg
Acceleration (a) = 10 m/s
Force (F) =?
F = ma
F = 35 × 10
F = 350 N
Thus, the Go Kart has a force of 350 N when the student locked the brake.
What is the resultant force acting on an object with an eastward force of
15 N and a northward force of 30 N?
Explanation:
15N in the north direction
What are valence electrons?
A. Electrons that determine what kind of element an atom is
B. Electrons at the very center of an atom
C. Electrons that are not involved in bonding
D. Electrons in an atom that can bond with other atoms
Answer:
The correct answer is D. Electrons in an atom that can bond with other atoms.
Explanation:
For those of you that need it still