Answer:
a. Chemical changes require a change in composition and physical does not
Explanation:
The main difference between physical and chemical changes is that chemical changes require a change in composition and physical does not.
A chemical change is the change in composition of a substance which is irreversible and a permanent change.
On the other hand, physical change is a temporary change in a substance and can be easily reversible. The composition of a substance do not change in physical composition.
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A girl preformed 50 j of work lifting a heavy box it took her 5 seconds to life the box. What was her power?
A. 45 W
B. 50 W
C. 10 W
D. 250 W
Explanation:
Power is change in energy over time.
P = (50 J) / (5 s)
P = 10 W
Answer: C
Explanation:
For this problem, we must divide.
50 ÷ 5 = 10
The answer to the question is 10
A penny is dropped from the top of a 240.0 m building and is in
free fall. How long will it take
the penny to hit the ground?
O 24.5 sec
3.5 sec
7 sec
O 5 sec
Answer:
It would take 5
18.3
Explanation:
It depends on how fast it comes and the timing
An object has an acceleration of 18.2 m/s/s. If the net force experienced by the object is
decreased by a factor of 3.9, then the new acceleration would be ___m/s/s. Enter a numerical
answer.
Answer:
46.2m/s²
Explanation:
Given parameters:
Acceleration = 18.2m/s²
Original force = F
Decrease factor = 3.9
Unknown:
New acceleration = ?
Solution:
Let the original force = F
new force = [tex]\frac{F}{0.39}[/tex]
Original acceleration = 18.2m/s²
new acceleration = ?
According to newton's second law of motion;
Force = mass x acceleration
So,
mass = [tex]\frac{Force}{Acceleration}[/tex]
So; initial mass = final mass
[tex]\frac{F }{18.2}[/tex] = [tex]\frac{\frac{F}{0.39} }{acceleration}[/tex]
[tex]\frac{F}{0.39}[/tex] x 18.2 = F x acceleration
Acceleration = 46.2m/s²
what will most likely happen if a sound wave moves from the air through a solid
a. it will increase wavelength
b. it will decrease in speed
c. it will increase in speed
d. it will decrease in wavelength
Answer:
C. it will increase in speed
Explanation:
brainliest please? :))
which of these is not a point source pollution
1. nitrates found in a river
2. someone dumping used oil in their backyard
3. factory smokestack
4. leaking oil tanker
It takes a car 28 hours to travel 2,009 miles. What is the average speed of the car
A) 71 mph
B) 71.5 mph
C) 75 mph
D) 71.75 mph
Answer:
D 71.75
Explanation:
divide 2,009 miles by 28 hours
is this right, please answer
The eyes, spinal cord, and brain are all main or key parts of the nervous system.
A car has an acceleration of -10.7 mph? What does this tell you about the motion of the care
A. It is speeding up
C. It is traveling at a constant speed
B. It is slowing down
D. It is traveling at a constant acceleration
Answer:
traveling at a constant acceleration
Convert the following from °C to K: For example, 0°C = 273 K, and -100°C = 173 K.
50°C
10°C
17°C
-40°C
Explanation:
To convert from °C to K, we use the expression below;
tK = t°C + 273
tK = temperature in Kelvin
t°C = temperature in celcius
A. 50°C;
tK = 50 + 273 = 323K
B. 10°C;
tK = 10 + 273 = 283K
C. 17°C;
tK = 17 + 273 = 290K
D, -40°C
tK = -40 + 273 = 233K
What wave is the safest of all the waves in the electromagnetic spectrum? Explain why.
Answer:
Radio waves.
Explanation:
Radio waves are at the far left of the EMS with a low frequency. Higher frequencies, such as Gama rays, cause more harm than the lower frequencies
J.J. Thomson discovered the electron in 1897. In 1904, he proposed a model of an atom, describing that there was an equal distribution of negative and positive charges throughout the atom. In 1909, Ernest Rutherford tested J.J. Thomson’s model by shooting positive particles at gold foil. Based on Thomson's model, it was predicted that the particles would fly through the foil with a small amount deflected back. Analyzing the results, Rutherford discovered that more of the particles bounced back than expected. Which of the following best explains how the results of Rutherford’s experiment affected Thomson’s widely-accepted atomic model?
Answer:
the answer is b : Rutherford’s results supported parts of Thomson's model, but also provided new data and interpretations.
Explanation:
i read that and read the answers this is only logical one
Darth Vader uses his powers to accelerate a 650.00 kg spaceship from rest to 100.00 m/s in 7.0 s. What is the net force on the spaceship?
Answer:
This Means Nothing to ME
Explanation:
I HAVE A tradition of doing a little analysis on one of my favorite movie franchises to celebrate Star Wars Day (May the Fourth Be With You). Given that Rogue One: A Star Wars Story recently appeared on DVD and various streaming services, I think its OK to look at that film without worrying about spoilers. In this case, I will calculate Darth Vader's power output as he uses the Force.
To calculate the power needed to lift this poor fellow, I can estimate how high Vader lifts him and at what speed. If I guess that the rebel is 1.75 meters tall (the average height of a man here on Earth, so I'll assume the same holds true on whatever planet the rebel calls home) then I can get an approximate scale for the scene. With that, I can use video analysis to plot the vertical position of the rebel as a function of time
Please help me to answer this.... I will mark as BRAINLIEST whoever answers the best!!!
Answer:
the first lens is a converging lens also called biconvex lens
and second is a diverging lens called biconcave lens
Explanation:
Which receives the most solar radiation?
A the polar zones
B the oceans
C the tempetra zones
D the equator
Which receives the most solar radiation?
A the polar zones
B the oceans
C the tempetra zones
D the equator ✅
How are forensic anthropologists and archaeologists different? A. Forensic anthropologists study bodies, and archaeologists search for artifacts. B. Forensic anthropologists study bodies, and archaeologists only study buildings. C. Forensic anthropologists study artifacts, and archaeologists study bodies. D. Forensic anthropologists study buildings, and archaeologists study bodies.
Answer:
A
Explanation:
Forensic anthropology is a branch of anthropology that analyzes the remains of a body in order to solve criminal cases. A forensic anthropologist, therefore, is a scientist that studies and analyzes remains of bodies in order to unravel criminal cases.
Archaeology, on the other hand, has to do with the analyses of artifacts in relation to human culture. An archaeologist is a person that studies artifacts mainly.
Hence, while a forensic anthropologist specializes in the study of bodies, archaeologist searches and studies artifacts.
The correct option is A.
A balloon has a mass of 104g and a volume of 7 cm. What is its density?
54 S
13.2
cm
14.868
Cm
0.07
cm
Answer:
14.868
Density equals mass divided by volume
A teacher placed 80 g of ice in a sealed plastic container at room
temperature.
How many grams of liquid water will be in the plastic container when the ice
has melted?
A. Slightly less than 80 g
B. Exactly 80 g
C. Slightly more than 80 g
D. The exact amount is unknown.
Answer: b
Explanation: Cause the other guy said it was
Answer:
The answer is B. Exactly 80 g
Explanation:
I just did the test and got it right!
Hope this helps.
1. A ball is dropped from the top of a cliff that is 38 meters tall. Calculate
the ball's impact velocity.
20 points
O +744.8
+27.29
+372.4
+19.30
Answer:
+27.29
Explanation:
To solve this problem we must use the following equation of kinematics.
[tex]v_{f}^{2} =v_{o}^{2}+2*g*x[/tex]
where:
Vf = final velocity [m/s]
Vo = initial velocity = 0 ( the ball is dropped)
g = gravity acceleration = 9.81 [m/s²]
x = distance = 38 [m]
Vf² = 0 + (2*9.81*38)
[tex]v_{f}=\sqrt{2*9.81*38} \\ v_{f} = 27.3 [m/s][/tex]
2. Essential Question - What is the smallest particle of sugar (glucose - C6 H12 O6) that is still sugar? Element or Molecule and explain why
PLeasseee help me!!
Answer:
Molecule
Explanation:
A molecule is the smallest particle of sugar (glucose - C6H12O6) or any other substance because a molecule possess all properties of that particular substance.
Molecules are responsible for all the chemical and physical properties of a substance, so molecules decided the properties of sugar as well. If the molecule will be broken, it will lose its properties. Sugar is composed of molecules that include 6 atoms of carbon, 12 atoms of hydrogen, and 6 atoms of oxygen.
Hence, the correct answer is "Molecule".
Where are nonmetals located in the periodic table?
along the bottom
along the upper right side
along the upper left side
in the middle
Answer:
along the upper right side
Explanation:
cause metals are on upper left side
A sprinter reaches a velocity of 2 m/s in just 1 second. At a constant rate of acceleration, how long does it take for her to double this velocity? What is her acceleration during this time period? Show you work and explain your answer.
Answer:
See the answer below
Explanation:
Acceleration is the ratio of velocity and time. Hence;
Acceleration of the sprinter = 2/1 = 2 m/s2.
When the acceleration is constant and the velocity is double:
acceleration = velocity/time
2 = 4/time,
time = 4/2 = 2 s
Hence, the time it will take for the velocity to double with constant acceleration is 2 s. The sprinter's acceleration during this period would be 2 m/s2.
Acceleration is the change in velocity with time. Hence, the time taken to double velocity is 2 seconds and the constant value of acceleration is 2m/s²
Acceleration is the change in velocity with time ;
Acceleration = (△velocity) ÷ time Velocity = 2m/s ; time = 1 secondAcceleration = (2 ÷ 1) = 2m/s²
Double the value of velocity = 2(2m/s) = 4m/s
At constant acceleration ; Acceleration = 2m/s²
Inputting the Values into the equation :
2 = 4 / time
(2 × time) = 4
Time = 4/2
Time = 2 seconds
Therefore, the time taken to double the velocity is 2 seconds
Learn more :https://brainly.com/question/20273577
2 points
Make the following conversion: 0.95km to cm Hint: don't forget king
henry.......
*
95,000 cm
0.000095 cm
9,500 cm
95 cm
Answer:
95000cm
Explanation:
Given parameter:
0.95km
Problem;
Convert km to cm;
Solution:
100cm = 1m
1000m = 1km
So,
100,000cm = 1km
1km = 100,000cm
0.95km = 0.95 x 100000 = 95000cm
On a aircraft carrier, a fighter jet goes from rest to a velocity of 250 mph (miles per hour) when it takes off. It does this in 3 seconds. What is it acceleration ?
Answer:
37.25m/s
Explanation:
Acceleration is the change in velocity of an object with respect to time.
Acceleration = velocity/time
Given
Velocity = 250mi/hr
Convert to m/s
1mile = 1609.344m
1hr = 3600s
250mi/hr = 250mi * 1609.344/1 * 3600
250mi/hr = 402366/3600
250mi/hr = 111.76m/s
Time = 3 seconds
Get the acceleration:
Acceleration = 111.76/3
Acceleration = 37.25m/s
Hence the acceleration is 37.25m/s
A car traveled 3000 m at a constant speed of 20 m/s. How long did it take to travel this distance?
Answer:
t = 150 [s]
Explanation:
To solve this problem we must take into account that the car travels at a constant speed, that is, there is no acceleration or it is equal to zero, therefore we can use the following equation of kinematics.
X = Xo + (v*t)
where:
x = final point [m]
Xo = initial point [m]
v = constant velocity = 20 [m/s]
t = time [s]
X - Xo = the distance traveled = 3000 [m]
3000 = 20*t
t = 150 [s]
LeBron James runs 260 meters East, then realized he dropped is basketball. He turns around and walks 54 meters West until he finds his ball. It takes him 45 seconds for the full trip. How far away is he from where he started?
Answer:
206 meters East
Explanation:
Assuming that the starting point of Lebron James 0. He ran from point 0 to 260 meters in the Eastern direction. His displacement is now 260 meters to the East.
He then turned from the Eastern to the Western direction - opposing directions - and then walked 54 meters to find his ball. His displacement from the starting point will now be:
260 - 54 = 206 meters in the Eastern direction.
What is the process of erosion?
Answer:
Erosion is the geological process in which earthen materials are worn away and transported by natural forces such as wind or water.
Explanation:
Destructive waves erode through four main processes; Hydraulic Action, Compression, Abrasion and Attrition.
Answer:
Below! ;)
Explanation:
Lots of people have the idea that erosion is where something is eroded away, and EVEN I thought that once, but erosion is the process in which parts of land are moved to a different province. Erosion can sometimes also bring in invacious species.
Hope this helps!
Have a nice day!
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A 12 volt battery is connected to two resistors in series. The first resistor has a resitance value of 5 Ohms and the current through the circuit is 1.5 Amps. What is the value of the second resistor? a. 9 Ohms b. 1.5 Ohms c. 5 Ohms d. 3 Ohms
Answer:
D. 3 Ohms
Explanation:
Give three reasons why it’s important to give children opportunities to pretend play or have make-believe situations
Answer:
The first reason for children to have pretend play is that it allows the child to learn how to interact socially. The child is able to take turns, share responsibility, develop how people feel and react the situation. Another reason is that it helps the child develop their critical thinking skills. They may have to creatively solve a problem, or think what they may need in real life for the pretend play. It increases the child's ability to think through those types of situations. The final reason it is important for a child to have pretend play is that it helps develop their language skills. If the child is imitating a dad, mom, teacher, etc. they will attempt to use the same language that person uses. This helps the child connect new language abilities and skills.
Explanation:
Answer:
The top 3 reasons for encouraging children to pretend play and make-believe include:
1. To encourage imagination and creativity.
2. To support social and emotional development.
3. To improve language and communication skills.
how does friction affect the speed
Answer:
Friction drag force causes objects to slow down as they move through a fluid, such as air or water. ... As an object's speed increases, the drag force from the fluid increases exponentially.
Answer:
Friction slows down an object using its rough surface
Explanation:
Friction is the force between objects. friction moves in the opposite direction which slows it down, it is very helpful when you want to stop a moving object
A ball is thrown up into the air. When it falls half-way back, what kind of energy does it have?
Answer:
it's gravitational potential energy would have converted to kinetic energy half way back when it's falls