Answer:
The dark lines in absorption spectrum of light is due capacity of atoms to absorb light of a specific energy. The absorption of light by atoms occurs when the atom transitions from a lower energy or ground state to an excited high energy state, and it appears in the emission spectrum of the element as dark lines located in the same position as the bright lines
Explanation:
a stone is projected horizontally with 20 m/a from top of a tall building. calculate it's position and velocity after 3s neglecting the air resistance
Answer:
1. 45 m
2. 50 m/s
Explanation:
From the question given above, the following data were obtained:
Initial velocity (u) = 20 m/s
Time (t) = 3 s
1. Determination of the position (i.e height)
Time (t) = 3 s
Acceleration due to gravity (g) = 10 m/s²
Height (h) =?
h = ½gt²
h = ½ × 10 × 3²
h = 5 × 9
h = 45 m
2. Determination of the velocity.
Initial velocity (u) = 20 m/s
Time (t) = 3 s
Acceleration due to gravity (g) = 10 m/s²
Velocity (v) =?
v = u + gt
v = 20 + (10 × 3)
v = 20 + 30
v = 50 m/s
A bicycle and a car start their journey at the same time the cyclist reaches it's top speed of 10mls in 15 the car reaches a speed if 15 MLS in55 which has the greater acceleration the car or the bicycle
Complete question is;
A bicycle and a car start their journey at the same time the cyclist reaches it's top speed of 10m/s in 15 s, the car reaches a speed of 15 m/s in 55 s. which has the greater acceleration the car or the bicycle.
Answer:
The bicycle has the greater acceleration.
Explanation:
Cyclist reaches a top speed of 10m/s in 15 s.
Formula for acceleration here is;
a = v/t
a = 10/15
a = 0.67 m/s²
Car reaches a speed of 15 m/s in 55 s.
Thus;
a = 15/55
a = 0.27 m/s²
From the 2 acceleration values gotten, we can say that;
The bicycle has the greater acceleration.
Suppose that you are standing on a train accelerating at 0.20g (where g is the acceleration due to gravity). What minimum coefficient of static friction must exist between your feet and the floor if you are not to slide
Answer:
0.2
Explanation:
The given parameters are;
The acceleration of the train, a = 0.2·g
The mass of the person standing on the train = m
Let μ represent the coefficient of static friction, we have;
The force acting on the person, F = m × a = m × 0.2·g
The force of friction acting between the feet and the floor, [tex]F_f[/tex] = m·g·μ
For the person not to slide we have;
The force acting on the person = The force of friction acting between the feet and the floor
F = [tex]F_f[/tex]
∴ m × 0.2·g = m·g·μ
From which we get;
0.2 = μ
The coefficient of static friction that must exist between the feet and the floor if the person is not to slide, μ = 0.2.
A car going around a curve with a radius of 15m experiences a centripetal acceleration of 2.5 m/s2. How fast is the car going?
0.17m/a
38 m/s
6.1 m/s
6.0 m/s
Answer:
Explanation:
The formula for centripetal acceleration is
[tex]a_c=\frac{v^2}{r}[/tex] . Filling in:
[tex]2.5=\frac{v^2}{15}[/tex] and
[tex]v=\sqrt{2.5(15)}[/tex] so
v = 6.1 m/s
Does the colour of an object affect the rate of evaporation?
Which statement is correct about how the temperature of an object changes?
Group of answer choices
The molecules making up object collide with the molecules of the other and some of the potential energy from a cooler object is transferred to the warmer one.
The molecules making up object collide with the molecules of the other and some of the kinetic energy from a warmer object is transferred to the cooler one.
The molecules making up object collide with the molecules of the other and some of the kinetic energy from a cooler object is transferred to the warmer one.
The molecules making up object collide with the molecules of the other and some of the potential energy from a warmer object is transferred to the cooler one.
The molecules making up object collide with the molecules of the other and some of the kinetic energy from a warmer object is transferred to the cooler one.
A ball of mass 0.3 kg is released from rest at a height of 8 m. How fast is it going when it hits the ground? (Gravity being equal to 9.8)
Answer:
Explanation:
Mass doesn't matter here because when something is falling, gravity plays fairly; an elephant falls at the same rate of acceleration as does a feather. What DOES matter is everything pertinent to the y-dimension of free-fall:
a = -9.8 m/s/s
v₀ = 0 (since the ball was held before it was dropped)
v = ??
Δx = -8 m (negative because the ball drops this far below the point from which it was released).
Putting all this together in one equation:
v² = v₀² + 2aΔx and filling in this equation:
v² = (0)² + 2(-9.8)(-8) and
v² = 156.8 so
v = 12.5 which rounds to 13 if you're using 2 sig figs, and rounds to 10 if you're only using 1 (which you should be, according to the way the numbers have been given in this problem)
define regular body in science
Answer:
All the sides and inner angles of a regular form must be equal. The sides and angles of an irregular form aren't the same. An equilateral triangle, for example, is a regular form because all of its sides and angles are the same length.
OAmalOHopeO
Gas to liquid with explanation on the basis of kinetic model and condensation point.
Answer:
Explanation:
1)Melting:
Melting is the process by which a substance changes from the solid phase to the liquid phase. ... Melting occurs when the internal energy of a solid increases, usually through the application of heat or pressure, such that the molecules become less ordered.
2) liquefication:
In physics and chemistry, the phase transitions from solid and gas to liquid (melting and condensation, respectively) may be referred to as liquefaction. The melting point (sometimes called liquefaction point) is the temperature and pressure at which a solid becomes a liquid.
3) vaporization:
Vaporization, conversion of a substance from the liquid or solid phase into the gaseous (vapour) phase. If conditions allow the formation of vapour bubbles within a liquid, the vaporization process is called boiling. Direct conversion from solid to vapour is called sublimation.
4) Sublimation occurs as molecules of a substance in the solid state go to the vapor state directly, rather than through the liquid state. ... ⭕In terms of the kinetic molecular theory, we know that molecules are in constant random motion, even when the substance is below the melting point.
Having the correct posture and the degree or severity of braking, acceleration and steering inputs have a direct result on the ability of a motorist to effectively address changes in __________?
Answer: Vehicle Balance
Explanation:
Vehicle balance simply means how the weight of a vehicle is distributed across its tires which connects to the road
It should be noted that there'll be a shift in the balance of a vehicle when the braking, acceleration, or turning bring about a scenario in which the weight of th vehicle moves from one area to another.
What is meant by measurement? l
Answer:
The action of measuring the size, length, or amount of something, as established is called measurement.
Explanation:
“Measurement” is the act of determining a target's size, length, weight, capacity, or other aspect. ... To use measurement tools as necessary. It is also appropriate to say that measurement is done by a worker using a measurement system, and instrumentation is done by a technician.
in a chemical equation, where do the products appear
Answer:
products would appear after the raw materials
Explanation:
raw material + raw material = product (anything deriving from combining two materials)
a 2kg object is dropped from height of 10m. ignoring air resistance calculate:
1. mechanical energy of the object
2. kinetic energy of the object when it is 3m above the ground
Answer:
ME= 196.2 J
KE= 136.2
Explanation:
potential energy=mgh 2*9.81*10
Our ME is quivalent to PE as that is the toal amount of energy in the system
Kinetic energy= 1/2 m[tex]v^{2}[/tex]
to solve for kinetic enrgy we need to use a kinaetmtic equation that help us find velocity
vf= vi+at
but we need to find time first
d=vi+1/2(accelretaion)[tex]t^{2}[/tex]
7=0+1/2(9.81)[tex]t^{2}[/tex]
t= 1.19 s
vf= 0+ 9.81*1.19
vf= 11.67 m/s
Now
1/2 m[tex]v^{2}[/tex]
1/2*2*[tex]11.67^{2}[/tex]
= 136. 2
or we could just (PE/10)*7
so (196.2/10)*7
Find the time taken if the speed of a train increased rom 72km/h to 90km/h for 234km
Answer:
2.89 hours
Explanation:
given :
Vo = 72 km/h
Vt = 90 km/h
S = 234 km
find : the time taken (t) = ?
solution :
2.a.s = Vt² - Vo²
2.a.(234) = 90²- 72²
468.a = 8100 - 5184
= 2916
a = 2916/468 = 6.23 km/h²
so,
t = (Vt-Vo) /a
= (90-72)/ 6.23
= 18/ 6.23
= 2.89 hours
Which type of stress is most likely the cause of irritability?
eustress
O hypostress
O distress
O peripheral stress
Answer:
The correct answer is - distress.
Explanation:
Eustress is a type of stress that is beneficial to person and caused by adrenaline. Hypostress is a stress that is caused due to boredom or no work. It is stress comes with wasting the time.
Distress is the bad stress caused by anxiety, sadness, grief, and such type of stress that is caused irritability. Irritability is caused not just by stress but many factors.
The material that would eventually make all the major bodies in our solar system first gathered together as smaller pieces which astronomers call:
Answer:
The answer is "planetesimals".
Explanation:
The uncountable little corpses of the accreted gas and dust were supposed to orbit the Sun while the planets were formed. The theory explaining the creation of the solar system as a whole is termed the quark-gluon plasma hypothesis.
An object produced by dust, rock, and other materials is called a planetesimal. This word is rooted throughout the microscopic idea, which shows that an object is too small to observe or quantify. Everywhere from many meters to hundreds of kilometers asteroids may acquire size.
Pls answer ASAP Which diagram shows a possible
sequence of steps in the research and development cycle? O A. New problem or discovery Engineering solution Development Research ОВ. Development Research Engineering solution New problem or discovery C. Research Development Engineering solution New problem or discovery OD. New problem or discovery Research Problem Engineering solution
Answer:
A. New problem or discovery Engineering solution Development Research Explanation:
A possible sequence of steps in the research and development cycle are A. New problem or discovery Engineering solution Development Research. In the research and development cycle, the first step is the problem that a scientist observe. After that we have discover a solution for that problem through many research so the above materials are the possible sequence of steps in the research and development cycle.
20 swings takes 5 seconds in the pendulum. calculate the periodic time of the swing
Answer:
0.25s
Explanation:
5/20 = 0.25s
This might be correct
A box of tools rests in the back of a pickup truck. The truck accelerates to the north and the box remains at rest in the truck. The direction of the friction force on the box of tools is _____.
Answer:
The direction of friction force is toards north.
Explanation:
A tool box is at rest on the back of a track. The truck is accelerating towards north.
As the frame of reference is acceleratinf so it is a non inertial frame of reference.
Thus, teh toolkit experineces a pseudo force towards the south direction.
According to the question, the toolbox is at rest so the fiction force is balances by teh psheudoforce, and thus teh friction force is acting toards north.
1. A rocket is forced forward by the ______ force of its engines, expelling gases out the rear of the rocket.
There are two forces acting on a rocket at the moment of lift off: Thrust pushes the rocket upwards by pushing gases downwards in the opposite direction.Weight is the force due to gravity pulling the rocket downwards towards the centre of the earth.So I'm thinking the answer is THRUST.
100 g of water are cooled and the enthalpy change is -12,540 J. What is the change in temperature of the water?
Answer:
-29.9907
Explanation:
c = Q / (mΔT)
You're looking for ΔT, so you would plug in what you already know and get C= -12540/(100 x ΔT)
then you would solve
the weight of body is less at moon than its weight is more at earth
Answer:
Gravity
Explanation:
There's no gravity on space so you're floating
A system of releases 125kJ of heat while 104kJ of work is done in the system. Calcilate the change om imternal energy (in kJ)
Answer:
DU = 21 KJ
Explanation:
Given the following data;
Quantity of heat = 125 KJ
Work = 104 KJ
To find the change in internal energy;
Mathematically, the change in internal energy of a system is given by the formula;
DU = Q - W
Where;
DU is the change in internal energy.
Q is the quantity of energy.
W is the work done.
Substituting into the formula, we have;
DU = 125 - 104
DU = 21 KJ
It takes 130 j of work to compress a certain spring 0.10m. (a) what is the force constant of this spring? To compress the spring an additional 0.10m, does it take 130
Answer:
Explanation:
The PE equation for a mass/spring system is
[tex]PE=\frac{1}{2}k[/tex]Δx² and filling in:
[tex]130=\frac{1}{2}k(.10)^2[/tex] and
[tex]k=\frac{2(130)}{(.10)^2}[/tex] so
k = 26000 N/m
If the displacement from equilibrium changes more, the PE needed to compress it will also change.
[tex]PE=\frac{1}{2}(26000)(.20)^2[/tex] gives us that
PE = 520J
An object is moving with an initial velocity of 9 m/s. It accelerates at a rate of 1.5 m/s2
over a time of 20 s. What is its new velocity?
Answer:
39 m/s²
Explanation:
initial Velocity (u) = 9m/s
acceleration (a) = 1.5m/s²
time(t) = 20s
V=u + at
V=9 + 1.5(20)
V=9 + 30
V=39m/s
Naomi Osaka, a Japanese-African-American tennis player is the 2021 Australian Open Champion, and the first Asian tennis player in Women's Tennis Association (WTA) history to be ranked first in Singles. To celebrate her win, Naomi Osaka hits a ball into the stands at 40. m/s and at an angle 30.° above the horizontal. On its way down, the ball is caught by a spectator 12 m above the point where the ball was hit.
a) Calculate the time it takes the tennis ball to reach the spectator.
b) Calculate the ball's horizontal range (horizontal distance travelled).
Answer:
(a) t = 0.75 s
(b) d = 26 m
Explanation:
Height, h = 12 m
Angle, A = 30 degree
initial velocity, u = 40 m/s
(a) Let the time is t.
Use second equation of motion
[tex]h = u t + 0.5 at^2\\\\12 = 40 sin 30 t - 0.5 \times10 \times t^2\\\\12 = 20 t - 5 t^2\\\\5 t^2 - 20 t + 12 =0 \\\\t = \frac{20\pm \sqrt{400-240}}{10}\\\\t = \frac{20\pm 12.65}{10}\\\\t = 3.3 s, 0.75 s[/tex]
(b) d = u cos A t
d = 40 x cos 30 x 0.75 = 26 m
Richard rides a bike on a road sloping downward and inclined at an angle of 30° with the horizontal. If he moves at a constant speed of 10 meters/second, calculate his vertical downward velocity.
Answer:
[tex]v_y = 5\ m/s[/tex]
Explanation:
The vertical downward component of the speed of the bike can be simply found out by using the following geometric formula:
[tex]v_y = vSin\theta[/tex]
where,
[tex]v_y[/tex] = vertical downward component of speed = ?
v = speed = 10 m/s
θ = angle of slope = 30°
Therefore,
[tex]v_y = (10\ m/s)Sin\ 30^o\\v_y = 5\ m/s[/tex]
what is energy
and how it works?
Answer:
Energy is defined as the ability to do work.
Explanation:
Energy is a property that must be transferred to a body to perform work on the body. Energy can be found in many things and can take different forms.Energy is never lost, but it can be converted from one form to another.Fossil fuels are the largest sources of energy for energy generation.Look at the distance-time graph below. It shows Angela's journey as she walks to the end of the road and back. The end of the road is 40 m away. After how many seconds did she arrive back where she started?
Answer:
Explanation:
If the distance to the end of the road was 40 m, and she traveled back to where she started, she traveled a total distance of 80 m. It took her 100 seconds to travel the 80 m.
Based on the given distance-time graph, the number of seconds that Angela used to go to the end of the road and arrive back is 100 seconds.
How long did Angela take?The end of the road is 40m and coming back is also 40 m. The total distance is:
= 40 + 40
= 80m
The graph shows that to walk 80 meters, Angela took a 100 seconds because the line on the graph ends at 80 m and 100 seconds.
Find out more uses of distance-time graphs at https://brainly.com/question/13877898.
#SPJ6
What does the temperature of the gas between galaxies in galaxy clusters tell us about the mass of the cluster
Answer:
HEY THERE!
Explanation:
The temperature tells us the average speeds of the gas particles, which are held in the cluster by gravity, so we can use these speeds to determine the cluster mass
HAVE A GOOD DAY!
