Answer:
[tex] \boxed{\sf Acceleration \ of \ the \ car = -5 \ m/s^2} [/tex]
Given:
Initial speed (u) = 30 m/s
Final speed (v) = 20 m/s
Time taken (t) = 2s
To Find:
Acceleration (a) of the car
Explanation:
From equation of motion we have:
[tex] \boxed{ \bold{v = u + at}}[/tex]
By substituting value of v, u & t in the equation we get:
[tex]\sf \implies 20 = 30 + a(2) \\ \\ \sf \implies 2a + 30 = 20 \\ \\ \sf \implies 2a = 20 - 30 \\ \\ \sf \implies 2a = - 10 \\ \\ \sf \implies a = - \frac{10}{2} \\ \\ \sf \implies a = - 5 \: m {s}^{ - 2} [/tex]
[tex] \therefore[/tex]
Acceleration (a) of the car = -5 m/s²
Two trains traveling towards one another on a straight track are 300m apart when the engineers on both trains become aware of the impending Collision and hit their brakes. The eastbound train, initially moving at 97.0 km/h Slows down at 3.50ms^2. The westbound train, initially moving at 127 km/h slows down at 4.20 m/s^2. What is the distance between them once they stop (express your answer to the two significant figures)
Answer:
48 m
Explanation:
Two trains traveling towards one another on a straight track are 300m apart when the engineers on both trains become aware of the impending Collision and hit their brakes. The eastbound train, initially moving at 97.0 km/h Slows down at 3.50ms^2. The westbound train, initially moving at 127 km/h slows down at 4.20 m/s^2.
The eastbound train
First convert km/h to m/s
(97 × 1000)/3600
97000/3600
26.944444 m/s
As the train is decelerating, final velocity V = 0 and acceleration a will be negative. Using third equation of motion
V^2 = U^2 - 2as
O = 26.944^2 - 2 × 3.5 S
726 = 7S
S = 726/7
S1 = 103.7 m
The westbound train
Convert km/h to m/s
(127×1000)/3600
127000/3600
35.2778 m/s
Using third equation of motion
V^2 = U^2 - 2as
0 = 35.2778^2 - 2 × 4.2 × S
1244.52 = 8.4S
S = 1244.52/8.4
S2 = 148.2 m
S1 + S2 = 103.7 + 148.2 = 251.86
The distance between them once they stop will be
300 - 251.86 = 48.14 m
Therefore, the distance between them once they stop is 48 metres approximately.
3.
In some countries, pedestrians attach reflective strips to their clothes or bags when they walk
outside during the night. Why do you think the pedestrians use these reflective strips?
Answer:
I think they use it at night because they want to avoid involving themselves in road accident while crossing the street. When there are reflective strips on their clothes, drivers do notice them even at far ends of the street since the strips will reflect the rays from the car lights to the driver,hence, the driver notifies that there is a pedestrian crossing and therefore slows down.
Q1: A runner is jogging in a straight line at a steady vr= 6.8 km/hr. When the runner is L= 2.4 km from the finish line, a bird begins flying straight from the runner to the finish line at vb= 13.6 km/hr (2 times as fast as the runner). When the bird reaches the finish line, it turns around and flies directly back to the runner. What cumulative distance does the bird travel? Even though the bird is a dodo, assume that it occupies only one point in space (a “zero” length bird), travels in a straight line, and that it can turn without loss of speed. Answer in units of km. Q2: After this first encounter, the bird then turns around and flies from the runner back to the finish line, turns around again and flies back to the runner. The bird repeats the back and forth trips until the runner reaches the finish line. How far does the bird travel from the beginning (including the distance traveled to the first encounter)? Answer in units of km.
Answer:
Q1: 3.2km
Q2: 4.8K
Explanation:
Q1:
So db is the distance of bird, and dr is the distance of runner
db = 2vr and the distance of bird is going to be 2 times greater than the runner.
formulas: db = 2vr & db = 2dr
db = 2drL + (L - x) = 2x2L - x = 2x2L = 3xx = [tex]\frac{2}{3}[/tex]LInsert it in x = [tex]\frac{2}{3}[/tex]L
[tex]\frac{2}{3}[/tex](2.4km) = 1.6km
Now we use formula db = 2dr
db = 2L - xdb = 2(2.4km) - 1.6kmdb = 3.2kmQ2:
Formulas: Vr = L /Δt & Vb = db/Δt
Vr = L/ Δt ⇒ Δt = [tex]\frac{L}{Vr}[/tex][tex]\frac{2.4km}{6.8km/hr}[/tex][tex]\frac{6}{17}hr[/tex](Km cancel each other)
Vb = db/Δt ⇒ db = VbΔt13.6km/hr[tex](\frac{6}{17}hr )[/tex]4.8km(hr cancel each other)
Hope it helps you :)
Which of the following is a characteristic of both scientific laws and theories? A. based on scientific evidence B. explain natural phenomena C. based on the opinions of scientists D. not subject to change
Answer:
A base on scientific event
Explanation:
theories can changeD
they dont explain unusual phenomenaB
Nothing is personal in scienceC
why are coal,nuclear,oil,and natural gas determined to be non-renewable types of energy resources
Answer:
Once used as a energy source they cannot be charged/used again.
Explanation:
A whale swims at a constant speed of 8m/s for 17s what distance did it travel
We have,
Speed = 8 m/s
Time = 17 seconds
Now,
Speed = Distance/Time
★ Substituting the values in the above formula,we get:
⇒ 8 = Distance/17
⇒ Distance = 8 × 17
⇒ Distance = 136 m
Hence,the distance covered by a whale is 136 m .
Determine the mass of the object below to the correct degree of precision.
272.83 g
272.9 g
272.90 g
272.94 g
Answer : The correct degree of precision is 272.94 g.
Explanation :
Precision : It is defined as the closeness of two or more measurements to each other.
For Example: If you weigh a given substance five times and you get 2.7 kg each time. Then the measurement is said to be precise.
Level of precision is determined by the maximum number of decimal places.
In the given figure, the value of mass of object is 280 g. From the given options we conclude that the 272.94 g is more close to 280 g and has maximum number of decimal places. So, 272.94 g measurement is said to be precise.
Therefore, the correct degree of precision is 272.94 g.
A scientist views an unknown cell under a microscope. Which of the following observations would support the claim that it is a plant cell rather than an animal cell? Choose 1 answer: (Choice A) A It has a cell membrane. (Choice B) B It has chloroplasts. (Choice C) C It is round in shape. (Choice D) D It has a nucleus.
Answer:
Choice A. It has chloroplast
Plants have chloroplast and animals dont
Explanation:
It having chloroplasts is the observation which would support the claim that it is a plant cell rather than an animal cell.
What is a Chloroplast?This is as organelle which produces the pigment known as chlorophyll and it is used during the process of photosynthesis.
Plants are known as primary producers and are involved in this process which is why option B was chosen.
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the unit for the measure of distance is
Answer: Well their are many Miles, inches, kilometres, meters, cementers, and so on.
hope it helps you bye
Centimetre, Meter, & Kilometre
Social science is a branch of science that deals with the nature of
A. human society
B. the physical world
C. animal societies
D. the medical field
Please select the best answer from the choices provided
А
B
why is it wrong to say a single object all alone is moving
Answer:
It is wrong to say that "a single object all alone is moving" simply because it goes against Newton's law of inertia.
Explanation:
From Newton's law of inertia, it states that: An object at rest or in constant motion will continue in it's present state unless it is acted upon by an external force.
Which means that a single object by itself cannot move anywhere unless it is acted upon by an external force..
Thus, it is wrong to say that "a single object all alone is moving" simply because it goes against Newton's law of inertia.
3. Which statement best describes the research projects that are funded by private
foundations?
a. Research projects that have little chance of success
b. Research projects for a specific cause
c. Research projects concerning the environment
d. Research projects that benefit consumers
Answer:
b. Research projects for a specific cause
Explanation:
Research funded by private foundations are usually for a specific cause. These type of research are usually properly scrutinized, and must have a high probability of success. Most of these projects may not be to benefit the consumers, but are usually done with a special purpose in mind.
Within the nebula that was the start of our solar system, a shock wave from an exploding supernova triggered dust particles to be drawn together to form a dense spherical cloud. The accumulation of dust set off a chain reaction. As the core of the cloud attracted more dust, its gravitational pull increased. As this pull increased so did all BUT its
Answer:
B expansion
Explanation:
In a cloud of gas and dust known as the solar nebula, the Sun and the planets jointly created 4.6 billion years ago. The solar nebula presumably collapsed as a result of a shock wave from a nearby supernova explosion. Thus, option A is correct.
What nebula that was the start of our solar system?A nearby supernova explosion's shock wave is most likely what caused the solar nebula to collapse.The planets formed in a thin disk around the Sun, which formed in the centre of the solar system. Moons began to form similarly around the gas giant planets.
Every speck of stuff in the solar system was once a massive nebula, or floating interstellar cloud, before it was shaped into a tidy collection of planets.
Therefore, a shock wave from an exploding supernova triggered dust particles to be drawn together to form a dense spherical cloud.
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Really easy it's physics.
What is the difference between centripetal force and centrifugal force???
Answer:
While centripetal force focuses towards the centre of a rotating path, the centrifugal force is just opposite to this, meaning it exerts a force to liberate a body from ...
Centripetal force is an inward force and centrifugal force is an outward force.
Centrifugal force is often referred to as inertial force or fictitious force.
More items...
Explanation:
16. Which of these provides most of the oxygen in Earth's
atmosphere?
coral reefs
rainforest plants
ocean phytoplankton
continental grasslands
Answer:
Ocean phytoplankton
Explanation:
The sea and ocean creates oxygen from the plants (sea creatures) that exist there. These plants generate oxygen when used as a-product of photosynthesis, a mechanism that transforms carbon dioxide through sunlight into carbohydrates that the body(plants) can use for nutrition.
WILL GIVE BRAINLIEST AND A THANKS TO FIRST CORRECT ANSWER!!!!
Which statements describe processes involved in the accretion of planetesimals and protoplanets? Check all that apply.
Both involve the melting of solid materials in the nebula.
Both involve the formation of solid particles from nebular materials.
Both involve the work of the gravitational push on nebular materials.
Both involve the trapping of gases and the clumping of masses of matter.
Both involve the growing of gas grains with the addition of atoms and molecules.
Answer: the answers are
(2)Both involve the formation of solid particles from nebular materials
And
(4)Both involve the trapping of gases and the clumping of masses of matter
Explanation:
Use the drop-down menus to complete each sentence.
The force applied to the physics cart is manipulated
Answer:b
Explanation:
Jon was happily riding his bike at a velocity of 12 m/s North, he soon realized he was late and increased his velocity to 24nm/s in the same direction in 6 seconds. What was his acceleration?
Answer:
2 m/s^2
Explanation:
acceleration formula: a=(v-v0)/t
a=(24-12)/6=2
Which transformation of energy occurs when a fan is turned on and the blades start to rotate?
Answer:
kinetic energy
Explanation:
A wind turbine transforms the mechanical energy of wind into electrical energy. A turbine takes the kinetic energy of a moving fluid, air in this case, and converts it to a rotary motion. As wind moves past the blades of a wind turbine, it moves or rotates the blades. These blades turn a generator
Select the correct equations that show that a freely falling rock drops a distance of 80 m when it falls from rest for 4 s .
Answer:
1 and 4
Explanation:
A ball of moist clay falls 17.3 m to the ground. It is in contact with the ground for 24.0 ms before stopping. (a) What is the average acceleration of
Answer:
Acceleration, [tex]767.08\ m/s^2[/tex]
Explanation:
Given that,
Height from a ball falls the ground, h = 17.3 m
It is in contact with the ground for 24.0 ms before stopping.
We need to find the average acceleration the ball during the time it is in contact with the ground.
Firstly, find the velocity when it reached the ground. So,
[tex]v^2=u^2+2ah[/tex]
u = initial velocity=0 m/s
a = acceleration=g
[tex]v=\sqrt{2gh} \\\\v=\sqrt{2\times 9.8\times 17.3} \\\\v=18.41\ m/s[/tex]
It is in negative direction, u = -18.41 m/s
Let a is average acceleration of the ball. Consider, v = and u = -18.41 m/s.
[tex]a=\dfrac{v-u}{t}\\\\a=\dfrac{0-18.41}{24\times 10^{-3}}\\\\a=767.08\ m/s^2[/tex]
So, the average acceleration of the ball during the time it is in contact is [tex]767.08\ m/s^2[/tex].
What is science? Science is observable, testable, replicable, reliable and flexible.
Answer:
Yes, the answer to the question is correct
Answer:
Here's what I know, As scientist discovered that Science is the method of learning everything about the natural world.
but your answer is quite correct above(◕ᴗ◕✿)
Li and Raj are playing football. They take turns trying to run past each other with the football. Li weighs 125 pound and Raj weighs 175 pounds. Li discovers that if he changes direction quickly when running, he can always dodge out of the way before Raj can tackle him.
Complete question is;
Li and Raj are playing football. They take turns trying to run past each other with the football. Li weighs 125 pound and Raj weighs 175 pounds. Li discovers that if he changes direction quickly when running, he can always dodge out of the way before Raj can tackle him.
Why is Li able to avoid Raj’s tackle? Choose the best description.
A) Raj has more mass and therefore more inertia, so he can change his motion more easily than Li.
B) Raj has more mass and therefore less inertia, so he can change his motion more easily than Li.
C) Li has less mass and therefore more inertia, so he can change his motion more easily than Raj.
D) Li has less mass and therefore less inertia, so he can change his motion more easily than Raj.
Answer:
Option D - Li has less mass and therefore less inertia, so he can change his motion more easily than Raj.
Explanation:
From Newton's first law of motion which is known as law of inertia, an object will remain at rest or continue in constant motion unless an external force acts upon it. This means that Inertia is simply the resistance of an object to any change in its state of rest or motion.
This means that the larger the mass of the object, the more resistance the object will have from an external force. Similarly, the smaller the object, the less resistance it will have from an external force.
Therefore, we can see that larger mass means larger resistance and in turn larger inertia while smaller mass denotes smaller resistance and in turn smaller inertia.
Now, from the question,Li weighs 125 pound and Raj weighs 175 pounds. So, Li has lesser mass than Raj, and so he also has less inertia. Thus, he can change his motion more easily than Raj due to that.
Answer:
Li has less mass and therefore less inertia, so he can change his motion more easily than Raj.
Explanation:
i did the test
What is 4.2 converted into grams
Explanation:
4.2 converted to grams equal 119.067997125
a person runs 27.0km west then turns around and runs 13.0km east what's the distance and displacement ?
Answer:
See below
Explanation:
Distance = 27 + 13 = 40 km
Displacement = 27 - 13 = 14 km
Three. Grams of the same substance in different phases are stored in three different containers. Each container is barely large enough to hold the substance
Complete question is;
Three grams of the same substance in different phases are stored in three different containers. Each container is barely large enough to hold the substance. Which statement can be known about the behavior of the atoms in each container?
A) The atoms in the solid would be moving vigorously around the container.
B) The atoms in the liquid would be vibrating in position.
C) The atoms in the solid would be vibrating in position.
D) The atoms in the gas would be moving slowly around the container.
Answer:
Option C - The atoms in the solid would be vibrating in position
Explanation:
Option A is wrong because the molecules in solids are held together by strong inter molecular forces and therefore can't move about freely but instead will vibrate in their position.
Option B is wrong because the atoms in liquid are more free than those in solids. Thus they will not have room to vibrate.
Option C is correct from the explanation from option A.
Option D is wrong because the atom of the gas would be very loose and free and would therefore be moving very fast around the container
Its c okay I was tryna help and u delete my question
The purpose of the sport called flight archery is to shoot an arrow the greatest possible distance. One of the greatest distances achieved in flight archery is 624 m. What would this distance be in centimeters?
Answer:
62400 cm
Explanation:
1 m = 100 cm
624m = 62 400 cm
how can you separate salt from sand
dissolve salt in water then pour the liquid away from the sand and then evaporate the water to recover the salt
New theories usually don’t start “from scratch.” For example, the modern model of the atom is the result of new information added to the cloud model. What is the main difference between the cloud model of the atom and the modern model? Group of answer choices Only the modern model includes protons. The cloud model does not include neutrons. Electrons move in specific orbits in the modern model. Electrons exist in a cloud around the nucleus in the cloud model.
Answer:
Electrons move in specific orbits in the modern model.
Explanation:
I'm still learning so, and D is not the answer.
The main difference between the cloud model of the atom and the modern model is that electrons exist in a cloud around the nucleus in the cloud model.
New theories usually don’t start “from scratch.” For example, the modern model of the atom is the result of new information added to the cloud model.
What is the main difference between the cloud model of the atom and the modern model?
Only the modern model includes protons. NO. Protons were discovered by Rutherford and are part of both models.The cloud model does not include neutrons. NO. Neutrons, discovered by Chadwick, are part of both models.Electrons move in specific orbits in the modern model. NO. Electrons in the modern model move in diffuse areas known as orbitals.Electrons exist in a cloud around the nucleus in the cloud model. YES.The main difference between the cloud model of the atom and the modern model is that electrons exist in a cloud around the nucleus in the cloud model.
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