If a train goes at constant speed of 40 miles per hour for one hour, then at constant
speed of 55 miles per hour for two hours, what is its average speed at the train?
Answer: because the train goes 72 mph for 2 hours
Explanation:
does the train go 72mph for 2 hours as well? if so the answer would be 324 because you have to add 90 twice scene it goes at that speed for 2 hours thats 180. assuming the train goes 72 mph for 2 hours it would be 144. then add 180 and 144 and you get 324 merry christmas and a happy newyear to you and your family
A block slides down a rough ramp with a 30-degree incline as shown.
Which diagram represents the forces acting on the block?
Answer:
Image 4 ?
Explanation:
Answer:
Image 4
Explanation:
Took Test
Which statements describe why organisms are classified? Check all that apply.
Answer:
what are the options for me
How does changing the number of neutrons affect an atom?
Answer:
If you change the number of neutrons in an atom, you get an isotope of the same element. The addition of a neutron can make an atom radioactive. When you change the number of protons in an atom, you will change the atom from one element to a different element.
Explanation:
The characteristics of the atomic nucleus allow to find the answer for the effect of the change of neutrons in an atoms is
The change in neutrons changes the atomic mass.
A chemical element is made up of protons, neutrons and electrons; the first two are in the atomic nucleus and the electrons are in orbits around them.
The number of protons corresponds to the atomic number and its change changes the type of element.
The neutrons that are neutral charge together with protons form the mass of the atom, as neutrons are neutral if the number does not affect the type of atom, but if its atomic mass changes.
Elements with the same atomic number, but different atomic mass, different number of neutrons are called isotopes; in general all elements have isotopes, for example hydrogen has an isotope called deuterium that has a neutral and another radioactive isotope called tritium that has two neutrons.
In conclusion using the characteristics of the atomic nucleus we find the answer for the effect of the change of neutrons in an atoms is
The change in neutrons changes the atomic mass.
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A water skier is towing by motorboat at a constant velocity of magnitude 15 km /h. The boat speed up, and after a short interval the skier is towed at a new constant velocity of magnitude 20 km/h. What is the net force on the skier when she is moving at 15 km/h? And at 20 km/h?
Answer:
The skier is experimenting a net force of 0 newtons in both cases. ([tex]v_{1} = 15\,\frac{km}{h}[/tex], [tex]v_{2} = 20\,\frac{km}{h}[/tex])
Explanation:
According to Newton's First Law, an object is in equilibrium when it is either at rest or moving at constant velocity, which means that net force is equal to 0 newtons.
Therefore, the skier is experimenting a net force of 0 newtons in both cases.
Five mL of ethanol has a mass of 3.9 g, and 5.0 mL of benzene has a mass of 44 g. Which liquid is denser?
Answer:
Benzene
Explanation:
A denser substance will have a higher or larger mass in the same volume. Therfore benzene will be a denser liquid as the mass is bigger in the same volume compared to ethonal.
You can also work this out by using the density formula which is mass of the substance over the unit of volume.
Please help ASAP WILL GIVE BRAINLIEST
why is it important to use the correct number of significant digits when reporting the results of an experiment
A. So other scientist can see how spread out your data are
B. So other scientists can see how many separate trials you preformed
C. So other scientists can compare their experimental results with yours
D. So other scientistcan see how precise your measurements were
Answer:
D
Explanation: It makes the most sense. Plz mark brainliest
Answer:
D
Explanation:
So other scientist can see how precise your measurements are
Someone please help me!
Answer:
a
Explanation:
How many meters did the car go in the first 4 seconds?
4. Hijackers are taking over a plane, They tell the pilot to get to Spain as fast as possible. The plane goes from 900
km/hr (beginning speed) to 1140 km/hr (final speed) in just 6 seconds. What is the acceleration of the plane?
How Can the human ear detect the sound
Answer:
Sound waves enter the outer ear and travel through a narrow passageway called the ear canal, which leads to the eardrum. The eardrum vibrates from the incoming sound waves and sends these vibrations to three tiny bones in the middle ear.
Explanation:
The eardrum vibrates from the incoming sound waves and sends these vibrations to three tiny bones in the middle ear. These bones are called the malleus, incus, and stapes.
12. Describe Binding energy and how it plays a role in nuclear fusion up to 56Fe (the synthesis of iron
nuclei). Include a description of the relationship between the strong nuclear force, the
electromagnetic force, and the number of nucleons involved in the fusion in your answer.
Help me on thiss one once again ughh ! asap ! hurry
What made the Fertile Crescent a good place for growing crops
Answer:
The Fertile Crescent was good for farming because of the fertility of its land, a result of irrigation from numerous large rivers in the region.
Explanation:
Please help my test is going on. Please answer both (i) and (ii).
Answer:
i. 7.5 m
ii. 15000 N
Explanation:
Area under vt graph shows the displacement
so area of triangle ABE= 1/2×15×2
=7.5 m
ii) F=ma
here, m=1000kg
and a=v-u/t
=15-0/1
a=15
F=1000×15=15000N
“While the big bang theory is the most popular modern theory of how the universe formed, it is incomplete.” Which question does the big bang theory leave unanswered?
Which answer choice correctly describes the ball's kinetic and potential energy? Group of answer choices The ball has more potential energy at position X than at position Z. The ball has more kinetic energy at position Y than at position W. The potential energy and kinetic energy of the ball are equal at position X. The potential energy and kinetic energy of the ball are greatest at position Z.
Answer:the ball has more kinetic energy at position Y than position X
Answer: G. The ball has more KE at position Y than at position W.
Explanation:
I’m just adding the picture here if you’re not sure if the question is the one you’re looking for. I take not credit for the answer, im just adding the picture.
How is ice more reflective than water??
Answer:
Because it has more texture and is solid. Its like glass
Explanation:
Answer:
Why is ice more reflective (has higher albedo) than liquid water? They're both the same substance (water). Is something quantum mechanical involved?
Explanation:
In fact ice is slightly less reflective than water. The reflectivity is related to the refractive index (in a rather complicated way) and the refractive index of ice is 1.31 while the refractive index of water is 1.33. The slightly lower refractive index of ice will cause a slightly lower reflectivity. In both cases the reflectivity is about 0.05 i.e. at an air/water or air/ice surface about 5% of the light is reflected.
A 5 Kg mass has an initial speed of 5m/s. After 3 sec, it has come to a speed of 70 m/s.
a. What is the acceleration of the mass?
b. What net force is acting on the mass during those 3 seconds?
Answer:
a
[tex]a = 21.7 \ m/s^2[/tex]
b
[tex]F = 108.5 \ N[/tex]
Explanation:
From the question we told that
The mass is m = 5 kg
The initial speed [tex]u = 5 m/s[/tex]
The time taken to attain [tex]v = 70 \ m/s[/tex] is t = 3 s
Generally from kinematic equation we have that
[tex]v = u + at[/tex]
=> [tex]70 = 5 + a * 3[/tex]
=> [tex]a = 21.7 \ m/s^2[/tex]
Generally the force acting is mathematically represented
[tex]F = m * a[/tex]
=> [tex]F = 5 * 21.7[/tex]
=> [tex]F = 108.5 \ N[/tex]
The photo shows dew drops that formed on the grass when temperatures
cooled during the night. Which change of state happened to form the dew?
A. Liquid to gas
B. Gas to liquid
C. Solid to gas
D. Gas to solid
The measurement of how much matter an object contains is its
a. volume.
b. weight.
c. mass.
d. melting point.
Answer:
Mass is how much matter an object contains. Mass and weight are different measurements, although they may seem similar. Mass is measured by comparing one object to another object of known mass. Grams and kilograms are units we use to measure mass.
The measurement of quantity of matter in an object is mass ( optionC)
What is mass of a body?Mass of a body is defined as the quantity of matter(Solid, liquid or gas) contained in the given volume of the body.
Mass is a scalar quantity and also part of the fundamental quantities. It is measured in kilograms. Other units of mass include; gram tonnes e.t.c
Matter is anything that takes up space and can be weighed.
Therefore the quantity of matter in a body is
called mass.
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If you poke a hole into a plastic bottle, and stick a straw in it, and then let the straw connect to a glass cup, and then blow a balloon and stick it on the top of the mouth of the bottle, we will measure how long it takes for the water to move from the plastic bottle to a cup.
Will a larger bottle size increase or decrease how fast water goes from the plastic bottle to the cup?
Describe a way to separate a mixture of fine sand and table salt without having to directly sort tiny crystals using tweezers.
Answer:
you can add water to the mixture and dissolve the salt
The method used is by solubility which is dissolving the sand and salt mixture into water and heating.
This is just about methods of separations of mixtures.
There are three major methods that can be used to separate a mixture of sand from salt. They are;
- Physical separation by use of magnifying glass and tweezers.
- Dissolving the mixture in water
- Melting the salt
The first method can't be used because we are told to use another method.
In that case, we will use the second option which involves solubility.Now, salt is made up of sodium chloride which means it is an ionic compound and it will be soluble in water whereas sand is not soluble in water as it contains mainly silicon dioxide.
Now, the process involved in this separation is as follows;- Pour the mixture into a container.
- Add water to the mixture in the container.
- Turn on a burner and heat this solution in the container till the salt has dissolved completely.
- Then after that, turn of the burner and allow the heated solution to cool off a bit.
- After it has cooled a bit, pour the salt solution on top into another empty container.
- Then collect the sand out of the heated container.
- Then heat the salt solution until the water dries and only the salt is left.
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Which dwarf planet orbits the Sun far beyond Pluto, taking 560 years per orbit?
Answer:
Eris
Explanation:
The object, temporarily designated 2003UB313 and later named Eris, orbits the sun about once every 560 years, its distance varying from about 38 to 98 AU.
Answer:
me
Explanation:
a car ends up at x = -245 m after a displacement of -103 m. what was its initial position?
Answer:
-142m
Explanation:
To find the initial position of the car, we can add the displacement.
-245 + 103 = -142
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2
How is acceleration related to force when mass is constant, according to Newton's second law of motion?
A. The acceleration is directly proportional to the net force,
OB
The acceleration is inversely proportional to the net force.
C. The acceleration is inversely proportional to the square root of the net force.
OD
The acceleration is directly proportional to the square root of the net force.
Reset
Next Question
Answer:
A
Explanation:
The acceleration of an object is directly proportional to its net force.
[tex]a = \frac{f}{m} [/tex]
Answer:
Correct choice: A. The acceleration is directly proportional to the net force
Explanation:
Newton's Second Law of Motion
According to Newton's second law of motion, the acceleration of an object is directly proportional to the net force F and inversely proportional to the object's mass m:
[tex]\displaystyle a=\frac{F}{m}[/tex]
Correct choice: A. The acceleration is directly proportional to the net force
a box is pushed along the ground with a force of 20N. If the box is pushed 0.5M.How much work done is on it?
Answer:
10J
Explanation:
work (W)= force (F)× distance (d)
W= 20N × o.5m
=10J (Joule)
Answer:
10 joules(j)
Explanation:
If a racer maintained a constant speed, during which sections of the race would the racer's velocity be the same?
Sections 1 and 2
Sections 2 and 3
Sections 2 and 4
Sections 3 and 4
pls help!!
Answer:
Sections 3 and 4
Explanation:
The correct answer would be sections 3 and 4.
The velocity of an object is the speed of the object in a particular direction. In this case, the speed of the racer is constant irrespective of the distance or the direction. Hence, the sections of the race during which the racer's velocity would be the same would be the sections in which the racer faces the same direction - which is sections 3 and 4.
what are two different examples of positive exeleration
Answer:Accelerating your car to get up to speed on a freeway
An airplane accelerating to take off
Accelerating out of the starting blocks at a track meet
Explanation:
Mass refers to the gravitational force on the matter in contact with the surface of a planet. true or false
Answer:
False
Explanation:
The mass of something does not depend on gravity. A planet has a constant gravitational force. Earth's is 9,80 N/kg. The moon, on the other hand, is 1,6 N/kg. the number of kilograms of something doesn't change if you go from one planet to another and since mass is measured in kilograms, mass doesn't change, therefore it does not refer to gravity. Mass refers to the quantity of matter in an object. It is weight that refers to the gravitational force on an object, since it is measured in newtons, and the amount of newtons per kilogram changes from planet to planet due to different gravity constants
A motorbike reaches a speed of 20 m/s over 60m, whilst
accelerating at 3m/s?, determine the bike's initial speed.
Initial speed = 2√10 m/s
Further explanationLinear motion consists of 2: constant velocity motion with constant velocity and uniformly accelerated motion with constant acceleration
An equation of uniformly accelerated motion
V = vo + at
Vt² = vo² + 2a (x-xo)
x = distance on t
vo / vi = initial speed
vt / vf = speed on t / final speed
a = acceleration
vf=20 m/s
d = 60 m
a = 3 m/s²
[tex]\tt vf^2=vi^2+2.ad\\\\20^2=vi^2+2\times 3\times 60\\\\400=vi^2+360\\\\40=vi^2\\\\vi=\sqrt{40}=2\sqrt{10}~m/s[/tex]