Answer:
Explanation:
Size of the image: 2 cmIn order to calculate the size of the image, we can use the following proportion:wherep = 80 m is the distance of the tree from the pinholeq = 20 cm = 0.2 m is the distance of the image from the pinhole = 8 m is the heigth of the object is the height of the imageBy re-arranging the proportion, we find2) Magnification: 0.0025The magnification of a camera is given by the ratio between the size of the image and the size of the real object:so, in this problem we have
b) Explain the method of preparing electromagnet. How do you test the
poles of an electromagnet with the help of magnetic compass ?
Answer:
An electromagnet is made by forming a coil around a soft iron bar (known here as the metal) such as a nail or screw and connect with an insulated copper wire (known here as the electric current conductor) the ends of the wound copper is then connected separately to the positive and negative terminals of a battery (known here as the source of electric current)
The north seeking needle of the magnetic compass will move away when brought close to the north pole of the formed electromagnet which can then be labelled N
The magnetic compass needle will be attracted to the south pole of the electromagnet which can then be labelled S
Explanation:
An electromagnet is an electric powered magnet that is formed (temporarily) by the perpendicular movement of electric current with respect to a metal core
The magnitude and the poles of an electromagnet can be changed by changing the magnitude and the direction of flow of the electric current respectively.
how many chromosomes does an elephant's egg cell have ?
Answer:
Diploid is often noted as 2N where N is the number of chromosomes. So in humans 2N=46. During sexual reproduction, the sex cells of parent organisms unite with one another and form a fertilized egg cell. In this situation, each sex cell is a gamete.
Explanation:
A ball hits a wall horizontally at 6m/s and rebounces at 4.4m/s the ball is in contact with wall for 0.04 sec. what is the acceleration.
Answer:
Acceleration (a) = 40 m/s²
Explanation:
Given:
Initial velocity (u) = 6 m/s
Final velocity (v) = 4.4 m/s
Time taken (t) = 0.04sec
Find:
Acceleration (a) = ?
Computation:
We know that,
⇒ v = u + at
⇒ a = (v - u) / t
⇒ Acceleration (a) = (4.4 - 6) / 0.04
⇒ Acceleration (a) = (-1.6) / 0.04
Acceleration (a) = 40 m/s²
A wire is placed between the poles of a horseshoe magnet. There is a current in the wire in the direction shown, and this causes a force to act on the wire.
A rubber band that has been stretched has gained ____ energy
OA) heat
OB) kinetic
OC) potential
D) chemical
Answer: potential
Explanation:
What happens to a sound wave as air temperature decreases?
A. The wave returns to rest a position
B. The wave’s speed decreases
C. Air particles push harder on the wave
D. The waves speed increases
Answer:
Explanation:
goes down as the temperature decreases, and vice versa. Sound's frequency is independent of temperature, while its speed is directly proportional to temperature. Heat, like sound, is a form of kinetic energy. Molecules at higher temperatures have more energy, thus they can vibrate faster. Since the molecules vibrate faster, sound waves can travel more quickly. ... This is faster than 331 meters per second, which is the speed of sound in air at freezing temperatures.
hope this helps!!!!
Sound waves travel more fastly in hot air , since particles in atmosphere gets more energetic in higher temperature. Hence, as the temperature decreases, the wave’s speed decreases.
What is sound waves ?Sound waves are mechanical waves passing through a medium. Sound waves are longitudinal where, the oscillation of particles is along the direction of wave propagation.
Compression waves, which at a microscopic scale rely on molecules transmitting energy one to another, are used to convey sound through the air.
Higher temperatures produce more energetic air molecules, which vibrate more rapidly. As a result of the molecules colliding with one another, the sound waves can move more quickly.
Therefore, as the temperature decreases, the speed of sound wave decreases. Thus, option B is correct.
Find more on sound waves:
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At what wavelength would a star radiate the greatest amount of energy if the star has a surface temperature of 60,000 K?
Answer:
[tex]\lambda=4.81\times 10^{-8}\ m[/tex]
Explanation:
We have,
The surface temperature of the star is 60,000 K
It is required to find the wavelength of a star that radiated greatest amount of energy. Wein's displacement law gives the relation between wavelength and temperature such that :
[tex]\lambda T=2.89\times 10^{-3}[/tex]
Here,
[tex]\lambda[/tex] = wavelength
[tex]\lambda=\dfrac{2.89\times 10^{-3}}{60000}\\\\\lambda=4.81\times 10^{-8}\ m[/tex]
So, the wavelength of the star is [tex]4.81\times 10^{-8}\ m[/tex].
What’s the When the temperature increases the viscosity of the liquids ??? Hurry someone plz help
Answer:
Decreases
Explanation:
Viscosity is inversely proportional to temperature
i.e. η ∝ [tex]\frac{1}{T}[/tex]
Where η is coefficient of viscosity and T is temperature,
Which means that when temperature increases, viscosity decreases and vice versa.
The gravitational force between two students sitting beside each other on Earth is
Answer:
Fgrav. = GM1×M2/R2
Explanation:
Gravitational force is mostly related
to planetary bodies by Newton's law of gravitation which states that the gravitional force is proportional to the product of the mass of the object and inversely proportional to the square of the distance between them.
Hence in this case the Gravitational force,
Fgrav. = GM1×M2/R2
M1 and M2 are the mass of the two students and R is their distance apart
G is a constant known as gravitational constant.6.67408 × 10-11 m3/kgs2
GENTE ME AJUDEM NESTA QUESTÃO POR FAVOR, TENHO PROVA ONLINE AMANHÃ! "Um sonar de um navio de pesca localizou um cardume de sardinhas a 300 m de profundidade. Sabendo que a velocidade de propagação do som na água tem o valor de 1500 m/s, calcula o tempo que decorre desde a emissão dos ultra-sons e a sua receção no navio." Por favor!
Answer:
The time between the emission of the wave and it's reception was 0.4 seconds.
Explanation:
The sound wave emitted by the sonar traveled from the boat to the fishes and came back, therefore the distance of it's total route is twice the distance from the boat to the fishes. We can apply the average speed formula in order to solve this problem, this is done below:
[tex]\text{speed} = \frac{\text{distance}}{\text{time}}[/tex]
We were given the distance traveled by the wave and it's speed, therefore we can solve for the time:
[tex]\text{time} = \frac{\text{distance}}{\text{speed}}\\\\\text{time} = \frac{(2*300)}{1500}\\\\\text{time} = \frac{600}{1500} = 0.4 \text{ s}[/tex]
The time between the emission of the wave and it's reception was 0.4 seconds.
drawing is a form of
Answer:
visual art in which one uses to mark drawing and express feelings
Explanation:
In my own opinion. Hope it helps.
Please give me concept to solve this.
Answer:
The difference in tension, between adjacent sections of the pull cable at the given conditions is 17.701 kN
Explanation:
We take the cars as moving upwards such that the resultant pulling force on the car, F, along the cable is given by the relation
[tex]F_{car}[/tex] = Upward tension force, [tex]Tension_{(upwards)}[/tex] - Downward tension force, [tex]Tension_{(downwards)}[/tex] - Component of the weight of the car along the taut cable
The parameters given are;
Mass of car, m = 2750 kg
Angle of inclination of taut cables, θ = 35°
The upward acceleration of the car, a = 0.81 m/s²
Given that the weight is acting vertically downwards, we have;
Component of the weight of the car along the taut cable = m × g × sin(θ)
∴ Component of the weight of the car along the taut cable = 2750 × 9.81 × sin (35°) = 15473.66 N
We therefore have;
[tex]F_{car}[/tex] = [tex]Tension_{(upwards)}[/tex] - [tex]Tension_{(downwards)}[/tex] - 15473.66 N
[tex]F_{car}[/tex] = m × a = 2750 × 0.81 = [tex]T_{upwards}[/tex] - [tex]T_{downwards}[/tex] - 15473.66
∴ [tex]Tension_{(upwards)}[/tex] - [tex]Tension_{(downwards)}[/tex] = 2750 × 0.81 + 15473.66 = 17701.16 N
Hence the difference in tension, [tex]Tension_{(upwards)}[/tex] - [tex]Tension_{(downwards)}[/tex] between adjacent sections of the pull cable if the cars are at the maximum permissible mass and are being accelerated up the incline = 17701.16 N or 17.701 kN.
How did Einstein’s and Newton’s theories differ in terms of explaining the cause of gravity?
Newton's law of universal gravitation doesn't say anything about the cause of gravity.
Einstein's theory of relativity does.
What are the eight states of matter?
SOMEONE HELP ME!!!!!
When describing image formation in mirrors, what is the angle of reflection?
Answer:
angle of refraction is the same as angle of incidence
Explanation:
Answer:
The angle of reflection is 180 degrees because if you mapped it on a coordinate plane, both the real object and the image in the mirror will be on opposite sides.
The graph shows the motion of a cyclist.
Calculate;
a) The acceleration in the first 20 s.
b) The acceleration between 20 and 30s.
c) The acceleration in the last 10 s.
d) The distance travelled by the cyclist when he was moving at a constant speed?
Show working.
Answer:
A. 0.5m/s².
B. –0.5m/s².
C. –0.5m/s².
D. 100m.
Explanation:
A. Determination of the acceleration in the first 20s.
Initial velocity (u) = 0
Final Velocity (v) = 10m/s
Time (t) = 20secs.
Acceleration (a) =..?
Acceleration = change in Velocity /time
a = (v – u)/t
a = (10 – 0)/20 = 10/20
a = 0.5m/s²
Therefore, the acceleration of the cyclist in the first 20secs is 0.5m/s²
B. Determination of the acceleration between 20 and 30s. This can be obtained as follow:
Initial velocity (u) = 10m/s
Final Velocity (v) = 5m/s
Time (t) = 30 – 20 = 10s
Acceleration (a) =..?
Acceleration = change in Velocity /time
a = (v – u)/t
a = (5 – 10)/10 = –5/10
a = –0.5m/s²
Therefore, the acceleration of the cyclist between the 20 and 30secs is
–0.5m/s².
C. Determination of the acceleration in the last 10s.
Initial velocity (u) = 5m/s
Final Velocity (v) = 0
Time (t) = 10s
Acceleration (a) =..?
Acceleration = change in Velocity /time
a = (v – u)/t
a = (0 – 5)/10 = –5/10
a = –0.5m/s²
Therefore, the acceleration of the cyclist between the last 10secs is
–0.5m/s².
D. Determination of the distance travelled by the cyclist when he was moving at a constant speed.
Velocity (v) = 5m/s
Time (t) = 50 – 30 = 20secs
Displacement (d) =?
Velocity = Displacement /Time
v = d/t
5 = d/20
Cross multiply
d = 5 x 20
d = 100m
Therefore, the distance travelled by the cyclist at constant speed is 100m
When is the magnitude of the acceleration of a mass on a spring at its maximum value?
A.
when the mass has a speed of zero
B.
when the mass is moving upward
C.
when the mass has no displacement
D.
when the mass is 1
2 x
Answer:
D
Explanation:
Now we know that Force is the rate of change of momentum meaning
F= mv/t
But
mv/t = Ke
v/t = ke/m
a= ke/m
Where a is acceleration
K is constant of proportionality of tension on a spring
e is the extension substended by a string.
From the formula of acceleration we can see that as mass decreases acceleration increases so we can see that m = 1
We would have a maximum value of acceleration.
The Answer Is....:
D.
When heat is converted into another form of energy, the total amount of energy is constant. Which law best illustrates this statement?
A.
the first law of thermodynamics
B.
the second law of thermodynamics
C.
the third law of thermodynamics
D.
none of the above
Answer:
A
Explanation:
This is the first law of thermodynamics and it's called the law of conservation of energy
Calculate the transfer of energy by a force of 15N when it moves the object by a distance of 5m
a. In the direction of the force
b. In a direction at 60° to the direction of the force
c. At right angles to the force
NEED EXPLAINATION
Answer:
a) 75 J
b) 37.5 J
c) 0
Explanation:
Work is the force exerted on an object causing it to move, Work is the product of force and displacement. Work is not done if the force and displacement are at right angles to each other. It is given by:
[tex]Work(energy)=Fxcos(\theta)[/tex]
F is the force, x is the displacement and Θ is the angle between force and displacement.
a) Force (F) = 15N and distance (x) = 5. Since it is in the direction of the force, Θ = 0
[tex]Work(energy)=Fxcos(\theta)= 15*5*cos(0)=75J[/tex]
b) Force (F) = 15N and distance (x) = 5. Θ = 60
[tex]Work(energy)=Fxcos(\theta)= 15*5*cos(60)=37.5J[/tex]
c) Force (F) = 15N and distance (x) = 5. Θ = 90
[tex]Work(energy)=Fxcos(\theta)= 15*5*cos(90)=0[/tex]
HELLO , PLZ HELP .
A diver is 20 m below the surface of the water in a dam. If the density of a water is 1000 kg/m3, determine the pressure due to the water on the diver. (Take g= 10 N/kg)
Answer:
the pressure due to the water on the diver is 200,000 pascal
pressure = height × density × acceleration due to gravity
p = 20×1000×10
p=200,000 pascal
SERE
At which temperature does the motion of atoms and molecules stop?
0°C
ОС
0°K
ОК
Answer: 0 Kelvin, or 0°K.
Explanation:
The Kelvin scale is used primarily in scientific applications due to the unit's lack of negative values.
0 Kelvin is equivalent to "absolute zero", or the temperature at which molecules and atoms no longer physically move.
0 Celsius on the other hand is a system based on the freezing and boiling points of water. 0 Celsius is the freezing point and 100 Celsius is the boiling point.
suppose that g (x) equals f (x + 1) - 3 which statement best compares the graph of g (x) with the graph of f (x)
Answer:
The graph of G(x) is the graph of F(x) shifted 1 unit to the left and 3 units down.
Explanation:
f(x + q) which is left q units
f(x - q) which is right q units
f(x) + q which is up q units
f(x) - q which down q nits
and
G(x) = F(x + 1) - 3
So,
f(x + 1) shifts to left 1 unit
f(x) - 3 shifts to down 3 units
So, the correct answer is B.
The graph of G(x) is the graph of F(x) shifted 1 unit to the left and 3 units down.
4 answers. Anyone know?
Answer:
lift
weight
thrust
air resistance
Explanation:
plz mark me as brainliest
Answer: Upthrust, lift, air resistance, and thrust
Explanation:
All of these 4 elements are taken into account during the design and creation of a plane.
Se realiza un trabajo mecanico de 3500 J para levantar una cubeta con area cuyo peso tiene una determinada magnitud. Determina la altura a la que se elevo la cubeta
Answer:
10 m
Explanation:
Trabajo (W) = 3500 J, peso de la cuchara (F) = 350 N.
El trabajo es el producto de la fuerza que actúa sobre un objeto y la distancia o desplazamiento. La unidad de trabajo estándar son los joules (J).
Trabajo (W) = fuerza (F) × distancia (d)
W = F × d
[tex]d=\frac{W}{F} =\frac{3500J}{350}=10m[/tex]
el cubo se elevó a 10 m
The height (distance) to which the bucket was raised is equal to 10 meters.
Given the following data:
Work done = 3500 JoulesWeight of bucket = 350 NewtonTo determine the height (distance) to which the bucket was raised:
Mathematically, work done is given by the formula:
[tex]Work\;done = Force \times distance[/tex]
Substituting the given parameters into the formula, we have;
Note: Force = weight.
[tex]3500 = 350 \times distance\\\\Distance = \frac{3500}{350}[/tex]
Distance = 10 meters.
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What is the force experienced when a 5.0 kg mass is accelerated at 7.5 m/s??
Answer:
F = 37.5 N
Explanation:
It is given that,
Mass of the object is 5 kg
Acceleration of the object is 7.5 m/s²
We need to find the force experienced by the object. The force is given by the product of mass and acceleration of an object. So,
F = m
[tex]F=5\times 7.5\\\\F=37.5\ N[/tex]
So, the force acting on the object is 37.5 N.
A 1380 kg car starts from rest at the top of a 28.0 m long hill inclined at 11.00 degrees. Ignoring friction, how fast is it going when it reaches the bottom of the hill?
Answer:
10.2 m/s
Explanation:
Using conservation of energy:
PE = KE
mgh = ½ mv²
v = √(2gh)
v = √(2 × 9.8 m/s² × 28.0 m × sin 11.0°)
v = 10.2 m/s
The velocity when car reaches the bottom of the hill is 10.2 m/s.
What is mechanical energy?The mechanical energy is the sum of kinetic energy and the potential energy of an object at any instant of time.
M.E = KE +PE
M.E = ½ mv² + mgh
where g is the acceleration due to gravity, v is the velocity, m is the mass and h is the height of the object.
Given is a 1380 kg car starts from rest at the top of a 28.0 m long hill inclined at 11.00 degrees.
Using conservation of energy principle, we have
PE = KE
mgh = ½ mv²
v = √(2gh)
Substitute the values, we get
v = √(2 × 9.8 m/s² × 28.0 m × sin 11.0°)
v = 10.2 m/s
Thus, the velocity when car reaches the bottom of the hill is 10.2 m/s.
Learn more about mechanical energy.
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The ________ of a particle for a given ‘Interval of time’ is defined as the ratio of total distance travelled to the total time taken.
uniform speed
average speed
uniform velocity
average velocity
Answer:
The average speed of a particle for a given ‘Interval of time’ is defined as the ratio of total distance travelled to the total time taken.
Explanation:
To find the average speed we take the total
distance traveled divided by the time interval.
A sheet of paper 3.0 cm by 4.0 cm is lying on the desk. If the atmospheric pressure is 1.013105 Pa, what is the total force exerted on the top side of the paper by the atmosphere?
Answer:
132.56N
Explanation:
Pressure is defined as force per unit area.
Expressed mathematically as;
P = F/A
Where P-pressure
F-force
A-area
From the above formula,
F= P×A
= 1.1013 × 10^5 × (3×4/10000)
= 11.013×12 =132.56N
Note: the unit of measure in cm is converted to m and since 100cm makes 1m for each sides 3cm and 4cm we convert to 'm' by dividing by 100 twice giving division by 10000)
The unit of measure Pa means Pascal and is the same as N/m2
What is the unit of work? Explain whether the unit of work is a fundamental uint
or derived unit
1.
What do you mean by a unit?
2.
unit or a derived unit.
are the fundamental units used in physics?
al Bureau of Weights and Me
Answer:
1)the unit of work is joule. 2)it is derived unit because it is made by two different unit force and displacement .3)
can someone help what are the common branches of physics
Answer: Dear Buddy ,the common brnches os physics are given below:
Explanation:
Mechanics
Classical physics
Modern physics
Thermodynamics
Electricity
Magnetism
Geo physics
Plasma physics
Optics
Sound and oscillation
Electronics
Chemical physics
Engineering physics
Solid state physics
Quantum physics
Nuclear physics
Particle physics
Bio physics
Astrophysics
Condensed matter physics
hope it helps
Answer:
Engineering is one of branches that uses physics mainly the most
Explanation:
as for engineering requires mathematics and physics principles in their everyday routine to calculate and measure accordingly to manufactur a product.