Answer:
Explanation:
a )
According to graph the object moves with constant velocity of 10 m /s during first 8 s and then its velocity changes to - 5 m /s from 8 th second upto 12 th second .
Initial displacement = 8 m
displacement during 8 s = velocity x time
= 8 x 10 = 80 m
total displacement = 88 m
b )
displacement during period from 8 th to 12 th s
= - 5 x 4 = - 20 m
total displacement after 12 s
= 88 - 20 = 68 m
c ) average speed = total distance covered during 12 s / total time
= (80 + 20) / 12
= 8.33 m /s
average velocity = total displacement during 12 s / total time
= 80 - 20 / 12
= 60 / 12
= 5 m /s .
The radius of a small ball is around 3.79747 cm. The radius of a basketball is about 3.16 times larger. What is the ratio of the surface areas of the small ball and a basketball? 2. What is the ratio of their volumes?
Explanation:
The ratio of the areas is the square of the ratio of the radii.
A/A = 3.16² = 9.99
The ratio of the volumes is the cube of the ratio of the radii.
V/V = 3.16³ = 31.6
A gauge is reading the pressure at the bottom of a river, at a depth of 6 m. Would the reading be greater or smaller than the reading at the bottom of a lake at the same depth? You must provide a clear explanation for full credit.
Answer:
The pressure at the bottom of the river is less than that at the bottom of the lake.
Explanation:
From Bernoulli's equation, the pressure difference is given by
ΔP = ρgΔh + ρ(v₂² - v₁²)/2 where ρ = density of water, g = acceleration due to gravity, Δh = depth, v₁ = velocity at top, v₂ = velocity at bottom
For the lake, v₁ = v₂, since the velocity at the top and bottom are the same. So,
ΔP₁ = ρgΔh + ρ(v₁² - v₁²)/2 = ρgΔh + 0 = ρgΔh
P₂ - P₁ = ρgΔh
P₂ = P₁ + ρgΔh
For the river, v₁ < v₂, since the velocity at the top of the river is greater than at the bottom.
So,
ΔP₂ = ρgΔh + ρ(v₂² - v₁²)/2.
Since v₁ < v₂, ρ(v₂² - v₁²)/2 will be negative,
So,
ΔP₂ = ρgΔh - ρ(v₂² - v₁²)/2.
Since ρ(v₂² - v₁²)/2 is negative, making ΔP less than that in the lake.
So, ΔP₂ = ΔP₁ - ρ(v₂² - v₁²)/2.
ΔP₂ = P₃ - P₁
P₃ - P₁ = P₂ - P₁ - ρ(v₂² - v₁²)/2.
P₃ = P₂ - ρ(v₂² - v₁²)/2.
where P₃ = pressure at bottom of the river and P₂ = pressure at bottom of the lake and P₁ = atmospheric pressure at top of river and lake respectively.
Since the factor ρ(v₂² - v₁²)/2 is removed from the pressure at the bottom of the lake, the pressure at the bottom of the river is therefore less than that at the bottom of the lake.
A baseball weights 1429 (0.142kg) were striked with force of 120N. Calculate its acceleration at
that time. Include the correct unit with your answer. Include one decimal place.
Answer:
a=845.07 m/s2
Explanation:
m=0.142kg
F=120N
a=?
F=m*a /:m
a=F/m
a=120N/0.142kg
a=845,07m/s2
Answer:
a = 845.07 m/s²
Explanation:
As we know ,
as per newton's 2nd law:-
F = ma
therefore
a = F/m
given:
a = ?
F = 120N
m = 0.142 kg
procedure:-
a = 120/0.142
therefore :
a = 845.07 m/s²
i) A 100 W and 60 W bulb are joined in series and connected to the mains. Which bulb will glow brighter? Why? ii) A 100 W and a 60 W bulb are joined in parallel to the mains. Which bulb will glow brighter? Why?
Answer:
i) 60 W
ii) 100 W
Explanation:
In each case, the bulb that dissipates the most power is the bulb that glows brighter. Power is voltage times current (P = VI). Using Ohm's law, we can rewrite this as P = I²R or P = V²/R.
Bulbs are rated at a certain power for a certain voltage. P = V²/R, so the bulb with the lower resistance will have the higher power rating. Therefore, the 100 W bulb has a lower resistance than the 60 W bulb.
i) They are in series, so they have the same current. P = I²R, so the bulb with the higher resistance will glow brighter. That's the 60 W bulb.
ii) They are in parallel, so they have the same voltage. P = V²/R, so the bulb with the lower resistance will glow brighter. That's the 100 W bulb.
Question 1 (2 points)
(01.01 LC)
Which of the following is a characteristic of science? (2 points)
QU
Reproducible by other scientists
Ob
The personal opinion of the scientist
С
Using variable conditions for each test
d
Including only the data that supports a hypothesis
Answer:
Reproducible by other scientists
Explanation:
I just took the test
if you ran 15 km/hr for 2.5 hours, how much distance would you cover?
Answer: 37.5 km
Explanation:
The question is that
If you ran 15 km/hr for 2.5 hours, how much distance would you cover ?
Where
Speed = 15 km/ hr
Time = 2.5 hours
Using the formula for speed.
Speed = distance/time
Substitute speed and time into the formula
15 = distance/ 2.5
Make distance the subject of formula by cross multiplying.
Distance = 15 × 2.5
Distance = 37.5 km.
3) An earth moving machine uses diesel oil, which when burnt will produce 3.0x10 9 J of energy. The work performed by the machine is 2.7x 10 8 J. What is the efficiency of the machine?
Answer:
The answer is below
Explanation:
The efficiency of a machine is the ratio of its output to its input. The efficiency shows how effective the machine by the way it converts the input energy into work. The higher the efficiency of the machine the more effective it is. The efficiency is usually less than 1.
Given that the machine uses diesel oil (input) that can produce 3.0 x 10⁹ J of energy while the work performed by the machine (output) is 2.7 x 10⁸ J. The efficiency is given as:
Efficiency = output / input = 2.7 x 10⁸ J / 3.0 x 10⁹ J = 0.09 = 9%
This means that the machine is not effective because of its low efficiency
On which factor mechanical advantage of simple machine depend on? Please help me and perfect answer will be brainlest answer.
Answer:
The factor that determines the mechanical advantage (or ideal mechanical advantage (IMA) - in the absence of frictional forces) in a simple machine is the ratio perpendicular distance of the applied force to the fulcrum to the perpendicular distance of the load to the fulcrum
The mechanical advantage can therefore by larger than 1 (requiring less force per load), or equal to 1 (effort equal to load) or less than 1( effort more than load)
Explanation:
placement.
A body is thrown vertically upwards. Its velocity keeps on decreasing. What happens
to its kinetic energy when its reaches the maximum height? Why?
If the speed of a body is increased four times, how will its kinetic energy be affected?
Answer:
kinetic energy will be equal to 0
Explanation:
this is because at final position velocity of body will become zero.
kinetic energy eill be 8 times
Identifying Energy Transformations
What is one energy transformation that is taking place when a plant is growing?
radiant energy to thermal energy
thermal energy to nuclear energy
O chemical energy to thermal energy
O radiant energy to chemical energy
Answer:
My answer is radiant energy to chemical energy because it uses the sun which is a form of solar energy and then converts the food to chemical energy for the plant itself
Answer: Radiant energy to chemical energy
Explanation: Right on edge2021
Match words at the left to the correct blanks in the sentences on the right. Not all words will be used.1. The energy that drives the expansion of a star into a subgiant or red giant comes from HYDROGEN SHELL FUSION2. Stars with mass greater than about 8 solar masses are considered HIGH-MASS STARS3. The final stage of core fusion in a low-mass star is HELIUM FUSION4. Stars that are fusing hydrogen in their cores are MAIN-SEQUENCE STARS5. When it dies, a high-mass star explodes as a SUPERNOVA6. A star that is expanding (into a subgiant and then a giant) has a(n) INERT HELIUM CORE7. When it dies, a low-mass star expels a PLANETARY NEBULA8. Stars with masses less than about two solar masses are considered LOW-MASS STARS
Answer:
In what way is iron unique among the elements?
It has the lowest mass per nuclear particle.
Match words at the left to the correct blanks in the sentences on the right. Not all words will be used.
-The energy that drives the expansion of a star into a subgiant or red giant comes from HYDROGEN SHELL FUSION
-Stars with mass greater than about 8 solar masses are considered HIGH-MASS STARS
-The final stage of core fusion in a low-mass star is HELIUM FUSION
-Stars that are fusing hydrogen in their cores are MAIN-SEQUENCE STARS
-When it dies, a high-mass star explodes as a SUPERNOVA
-A star that is expanding (into a subgiant and then a giant) has a(n) INERT HELIUM CORE
-When it dies, a low-mass star expels a PLANETARY NEBULA
-Stars with masses less than about two solar masses are considered LOW-MASS STARS
what is the function of eye lens of the human eye
Answer:
Lens of the human Eye is a important and one of that most complex sense organ.
Explanation:
Lens of the human eye it helps that in visualizing light and color perception and objects , glance on the human eye structure and function.
Sense organs are much pretty similar to the camera they help us see the objects clear.
A human eye is the 2.3 cm in diameter and all filled some fluid, and there are following parts in eye:- cornea, Retina , Lens ,Pupil , optic nerves.
cornea :- the cornea is the first transparent part of is called cornea, enters the light through the cornea.
Retina :-it is light sensitive layer that consists of nerve cells,then transmitted to the brain through nerves.
Lens:- behind the pupil there is a transparent structure called lens,it shape focus light on the retina.
Pupil:-it control the value of light that enters the human eye.
Optic nerves is are the two types :- (1) cones (2) Rods .
Answer:
It causes Light Rays to converge on the retina
Explanation:
I took the K12 Test
2. Adelia holds a shiny steel spoon with its back (convex surface) facing her eyes at a distance
of approximately 30 cm. She sees an upright image of herself. However, when the spoon
is changed so that the front (concave surface) of the spoon is facing her eyes, an inverted
image is observed.
(a) Explain this situation.
(b) Why is an upright image not seen on the front surface of the spoon at that distance?
Answer:
(a) The convex mirror image, is always upright at all positions, while images formed by concave mirrors are always inverted when the object distance from the mirror is more than the mirrors focal length.
(b) An upright image is not seen for object at a distance from a concave mirror further than the focal length of the mirror, which is the spoon in the question
Therefore, the location of her eyes of approximately, 30 cm, from the mirror is more than the mirror's focal length
Explanation:
Solve for angles A-D
1-A boy rolls a toy car across a floor with a velocity of 3.21 m/s. How long does it take the car to travel a distance of 4.50 m?
A-0.71s
B-1.40s
C-2.9s
D-14s
2-A girl heads out for a jog and runs at 2.95 m/s, due North, for 3600 s. How far did she run?
A-0.194 x 10^-4
B-1220m
C-5240
D-10620
3-A car is traveling South on I-85. It travels between two exits that are 5.40 km apart in 4.85 minutes. What is the average velocity of the car in m/s?
A-8.42m/s
B-12.8m/s
C-14.9m/s
D-18.6m/s
4-An airplane takes 1.30 hours to travel to an airport north of Atlanta. If the average speed of the plane is 134 m/s, what is the plane's displacement as measured from Atlanta?
A-129,324m=129,000m rounded
B-356,247m=356,000m rounded
C-498,782m=499,000m rounded
D-627,120m=627,000m rounded
5-How long does it take a sailboat traveling 18.0 m/s to go 15.7 km west?
A-15,000s
B-872s
C-594s
D-326s
A disk-shaped dough is initially spinning at 2 rotations per second (1 rotation = 360°). As time goes on, it slowly deforms, and is now spinning at a different angular speed. The dough changed radius from 16 cm to 17 cm, and its mass remained constant throughout. What is its final angular speed in degrees/s?
Answer:
10.44° per sec
Explanation:
Initial angular speed N = 2 rotations per minute
converting to rad/s ω = 2πN/60 = (2 x 3.142 x 2)/60 = 0.21 rad/s
the initial radius of the disk = 16 cm = 0.16 m
final radius = 17 cm = 0.17 m
Angular momentum = [tex]I[/tex]ω
where [tex]I[/tex] = rotational inertia = mass x [tex]radius^{2}[/tex]
ω = angular speed
For the initial case
[tex]I[/tex] = m x [tex]0.16^{2}[/tex] = 0.0256m
Angular momentum = 0.0256m x 0.21 = 0.0054m
For second case
[tex]I[/tex] = m x [tex]0.17^{2}[/tex] = 0.0289m
Angular momentum = 0.0289m x ω = 0.0289mω
For conservation of rotational momentum, initial angular momentum must be equal to the final angular momentum
0.0054m = 0.0289mω
m cancels out, we have
0.0054 = 0.0289ω
ω = 0.187 rad/s
converting back to rpm, we have
N = 0.187/2π = 0.029 rotations per sec
0.029 x 360 = 10.44° per sec
16. Two of Jupiter's Galilean moons, lo and
Europe, make a complete revolution around it
over the periods T1=1.77 days and T2 = 3.55
days. Knowing that lo revolves around Jupiter
at a distance of 421600 km, determine the
linear velocity of Europe's motion in its orbit.
Answer:
The linear velocity of europe's motion in its orbit is 7875.58 km/hr.
Explanation:
Given that,
Time period of lo = 1.77 days
Time period of europa = 3.55 days
Distance of lo from jupiter = 421600 km
We know that,
Distance of europa from jupiter = 671000 km
We need to calculate the linear velocity of europe's motion in its orbit
Using formula of velocity
[tex]v=\dfrac{d}{t}[/tex]
Where, d = distance between europa and jupiter
t = time
Put the value into the formula
[tex]v=\dfrac{671000}{3.55\times24}[/tex]
[tex]v=7875.58\ km/hr[/tex]
Hence, The linear velocity of europe's motion in its orbit is 7875.58 km/hr.
Determine whether each sum, difference, product,
or quotient represents a rational number or an
irrational number. Explain how you know without
simplifying
Explanation:
The asked in the Question is missing, although i am assuming the number
as [tex]\frac{6}{23}[/tex] ÷[tex]\frac{\sqrt{2} }{2}[/tex].
The given expression contains an irrational number. So, the quotient will also be an irrational number.
Solving
[tex]\frac{6}{23}\times\frac{\sqrt{2} }{2} \\=\frac{3\sqrt{2} }{23}[/tex]
Which is an irrational number.
obesity occurs due to (a) overeating of carbohydrates and fats(b) not eating enough carbohydrates and fats (c) overeating of vitamins and minerals (d) not eating enough vitamins and minerals
Answer:
B for BIG
Explanation:
carbs and fats is energy, if not being use or burned off, it'll be becomes body fat.
The rhinestones in costume jewelry are glass with index of refraction 1.50. To make them more reflective, they are often coated with a layer of silicon monoxide of index of refraction 2.00. What is the minimum coating thickness needed to ensure that light of wavelength 480 nm and of perpendicular incidence will be reflected from the two surfaces of the coating with fully constructive interference?
Answer:
60
Explanation:
According to the given question, the computation of minimum coating thickness is shown below:-
The condition for constructive interference is
[tex]2t_{min} = (m + \frac{1}{2} )\times \frac{\lambda}{^nmateral}[/tex]
[tex]= (0 + \frac{1}{2} )\times \frac{\lambda}{^nmateral}[/tex]
[tex]t = \frac{\lambda}{4n}[/tex]
Now we will put the values to the above formula to reach the answer
[tex]= \frac{480nm}{4\times 2.0}[/tex]
= 60
Therefore we simply applied the above formula to determine the minimum coating thickness
The minimum coating thickness needed to ensure that light of wavelength 480 nm and of perpendicular incidence will be reflected from the two surfaces of the coating with fully constructive interference is 60.
Given that, the index of refraction of glass is 1.50 and the index of refraction of silicon monoxide is 2.00. The wavelength light of 480 nm.
If [tex]\lambda {c}[/tex] is the wavelength in the coating and λ is the wavelength in vacuum, then [tex]\lambda_{c} = \dfrac {\lambda}{n}[/tex] where n is the index of refraction of the coating.
Thus, the minimum coating thickness [tex]T_{min}[/tex] can be calculated as,
[tex]2T_{min} = (m+\dfrac {1}{2})\times\dfrac {\lambda} {n}\\\\T_{min} = (m+\dfrac {1}{2}) \times\dfrac {\lambda} {2n}[/tex].
For the constructive interference, m = 0.
So [tex]T_{min} = \dfrac {\lambda} {4n}[/tex]
[tex]T_{min} = \dfrac {480\rm nm} {4\times2.0}[/tex]
[tex]T_{min} = 60[/tex]
The minimum coating thickness needed to ensure that light of wavelength 480 nm and of perpendicular incidence will be reflected from the two surfaces of the coating with fully constructive interference is 60.
For more details, follow the link given below.
https://brainly.com/question/15541641.
Monochromatic light shines on the cathode in a photoelectric effect experiment, causing the emission of electrons. If the frequency of the light stays the same but the intensity of the light shining on the cathode is increased:_________
a. The emitted electrons will be moving at a higher speed.
b. There will be more electrons emitted.
c. Neither A nor B are true.
d. Both A and B are true
Answer:
b. There will be more electrons emitted.
Explanation:
In photoelectric emission, the energy of the emitted electron is dependent on the frequency of the wave incident on the plate; but not the intensity. The rate of electron emission per unit time however depends on the intensity of the incident light. So increasing the intensity of the light at constant frequency will only affect the number of electrons emitted per unit time.
Will mark as BRAINLIEST......
A balloon is ascending at the rate of 4.9 m/s. A packet is dropped from from the balloon when situated at a height of 100m.
How long does it take the packet to reach the ground ?
What is it's final velocity ?
Answer:
t = 5.04secsv = -44.49m/sExplanation:
Given parameters
initial velocity u = 4.9m/s
height of drop H = 100m
acceleration due to gravity g = -9.8m/s²(since the body is ascending i.e moving against gravity)
Required
time taken by the packet to reach the ground 't'
Using the equation of motion
S = ut+1/2gt²
0-100 = 4.9t+1/2(-9.8)t²
-100 = 4.9t-1/2(9.8)t²
-100 = 4.9t-4.9t²
4.9t-4.9t² +100 = 0
4.9t²-4.9t² -100 = 0
Multiplying through by 10
49t²-49t-1000 = 0
Using the general equation t = (-b±√b²-4ac)/2a
t = -(-49)±√(-49)²-4(49)(-1000)/2(49)
t = 49±√(2401+196000)/2(49)
t = 49±√(198401)/98
t = 49±√(198401)/98
t = 49±449.42/98
t = (49+449.42)/98
t = 494.42/98
t = 5.04secs
Hence, it took the packet 5.04secs to reach the ground
The final velocity is calculated using the formula v = u + at
v = u-gt
v = 4.9-(9.8)(5.04)
v = 4.9-49.392
v = -44.492m/s
This shows that the final velocity is 44.49m/s(moving downwards)
A stone is dropped from the same height at Terai and at the top of the
mountain. Where does it fall faster? Why?
Answer:
It will fall at the same speed in both locations
Explanation:
When an object is falling, it is accelerated to the same degree irrespective of the height from which it is falling.
All objects on the earth's surface experience an acceleration due to gravity. This acceleration due to gravity is the same for all objects irrespective of their height or mass.
Hence for a stone dropped from the same height as Terai and the top of a mountain, the acceleration due to gravity is the same in both cases hence they will fall at the same speed.
Use the diagram to answer each question.
Why might a researcher further classify the data in the chimpanzee dier table to include separate information of males and females ?
Answer:
In the data table, we can see the frequency distribution in the diet of a given type of chimpanzee.
Why a researcher further classify the data separating information of males and females?
Well, the objective of the researcher is to find information about these chimpanzees, so if he notices that the diet varies (even slightly) between males and females, separating the information between males and females would be useful to know how the diet varies, and why this happens.
This is the primary motive of why a researcher would want to separate the information of males and females.
A stationary siren creates an 894 Hz
sound. When a motorcyclist is driving
toward it, she hears a 926 Hz sound
How fast is she driving?
(Speed of sound = 343 m/s)
(Unit = m/s)
Answer:
12.3 m/s
Explanation:
The Doppler equation describes how sound frequency depends on relative velocities:
fr = fs (c + vr)/(c + vs),
where fr is the frequency heard by the receiver,
fs is the frequency emitted at the source,
c is the speed of sound,
vr is the velocity of the receiver,
and vs is the velocity of the source.
Note: vr is positive if the receiver is moving towards the source, negative if away.
Conversely, vs is positive if the receiver is moving away from the source, and negative if towards.
Given:
fs = 894 Hz
fr = 926 Hz
c = 343 m/s
vs = 0 m/s
Find: vr
926 = 894 (343 + vr) / (343 + 0)
vr = 12.3
The speed of the car is 12.3 m/s.
John owns a used 2003 mustang Mach 1, he spots a news crew with a bunch of people what should he do? A) Rev his engine at the highest RPM B) Do a burnout C) Drive near the Crowd and drop a gear and hurl into the crowd D) ALL OF THE ABOVE
Each of the three choices is tasteless, exhibitionist, juvenile, and dangerous. John should do none of them.
Encountering a news crew, there's no reason for John to call attention to himself in a childish way, or interfere with their work in any way.
What he should do is:
==> Slow down
==> Pass the scene cautiously
==> Resume his normal, legal speed quietly, in case the crew happens to be recording audio at the moment.
Mysteriously, this course of action is nowhere to be found among the choices listed.
Answer:
all three options :)
Explanation:
cuz merica
The particles of a GAS within a closed container will collide with the container walls, exerting a FORCE. The force per unit of AREA is known as what?
Answer:
Pressure
Explanation:
One of the theories propounded by the Kinetic molecular theory, and which also provides an explanation of the several gas laws, is the statement that the gas molecules in a container, travel in straight lines and are in constant collision with themselves and the walls of the container, thus exerting force. This force is the pressure which is defined as the force per unit area.
There is no loss of energy in the collisions involving the gas molecules and that is why their movement can be described as elastic. The descriptions of the behavior of gas molecules in the Kinetic Molecular Theory, give rise to Charles law, Boyle's Law, Avogadro's Laws, Dalton's Law, and Amonton's Law.
Answer:
The pressure
Explanation:
Molecules of gases are constantly in motion, colliding with the walls of their container. This constant collision impacts force on the walls of the container, which depends on the speed with which the molecules are moving. The speed with which these molecules travel depends on the average kinetic energy of the molecules, which is proportional to the temperature.
This force when exerted per unit area is the pressure the gases exert on the walls of the container.
Question 2 of 10
Which of the following is an Sl unit?
A. Foot
B. Inch
C. Meter
D. Mile
SUBMIT
Answer:
C. Meter
Explanation:
The International System of Unit (SI) is gotten from the french word Systeme international is a modern form of metric measurement. It is the system of measurement that is universally accepted. It is from this SI units that all other system of units are derived. There are seven basic SI units which are:
1) Length in Meter (m)
2) Time in Seconds (s)
3) Amount of Substance in mole (m)
4) Electric current in ampere (A)
5) Temperature in kelvin (k)
6) Luminous intensity in candela (cd)
7) Mass in kilogram (kg)
Open the attached image to see the question.
Answer:
option A
Explanation:
STOVE RADIATE ENERGY
(02.10 LC)
Which American sport stems from a combination of the British sports rugby and soccer?
Baseball
Basketball
Tennis
Football
Question 2 Multiple Choice Worth 5 points)
Answer:
football
Explanation:
I took the 2.10 quiz and got it wrong so it must be football