Answer:
The second knife-edge must be placed 46.2 cm from the zero mark of the rod.
Explanation:
From the law of equilibrium, ΣF = 0 and ΣM = 0.
Let R be the reaction at the knife edge. Since the weight of the rod and zinc load act downward, and we take downward position as negative
-32 N - 2 N + R = 0
-34 N = -R
R = 34 N
Also, let us assume the knife-edge is x cm from the zero mark. Taking moments about the weight and assuming the knife-edge is right of the weight of the rod. Taking clockwise moments as positive and anti-clockwise moments as negative,
-(45 - 25)2 + (x - 45)R = 0
-(20)2 + (x - 45)34 = 0
-40 = -(x - 45)34
x - 45 = 40/34
x - 45 = 1.18
x = 45 + 1.18
x = 46.18 cm
x ≅ 46.2 cm
The second knife-edge must be placed 46.2 cm from the zero mark of the rod.
Apply Newton's first law to music playing on the radio.
Answer: Find the answer in the explanation
Explanation:
The music playing on the radio will be heard through the sound waves coming from the radio.
The travelling wave will obey Newton's first law of motion which state that:
An object or particle will remain at rest or continue its linear motion in a straight line except an external force is applied.
The external force through wind could affect the travelling of the sound waves. Since the wave is longitudinal wave. That is, it needs a medium (air) for its propagation.
!! i will mark as brainliest !!
A student investigated how the resistance of a piece of nichrome wire varies with length. Describe how the student would obtain the data needed for the investigation.
the answer should include a risk assessment for one hazard in the investigation.
1) The length of the wire needs to be measured and varied (this is order to get a complete set of results for your experiment )2) Then go through each length of wire and measure the current and potential difference for each wire. (in order to calculate resistance later )3) repeat multiple times for each length of wire in order to create an average = sum/n (if need be explain difference between accuracy and precision).4)calculate resistance using equation resistance * current = Voltage for each length of wire
Hazards: Electric shock due to current , overheating wire can overheat , can be minimised by using low currents.
As the length of the nichrome wire will increase then the resistance in the wire will also increase and if the length of the nichrome wire will decrease then the resistance in the wire will also decrease because the resistance is directly proportional to the length of the wire.
What is Resistance?A force that opposes the flow of current is electrical resistance, often known as resistance to electricity. It acts as a gauge for how challenging it is for current to flow in this fashion. Ohms (Ω), which represent resistance values, are used.
Electricity will move from high to low when an electron difference exists between two terminals. This flow is opposed by resistance. Lower currents occur at higher resistance levels. The opposite is also true: the current increases as the resistance decreases.
As the length of the wire increase then the resistance increases automatically similarly if the length is reduced the resistance will also get reduced because length is directly proportional to the resistance in the wire. One more thing is that if the resistance in the wire increase then the heating in the wire will also increase and vice versa because resistance in the wire is directly proportional to the heating effect in the wire.
To get more information about Resistance :
https://brainly.com/question/11431009
#SPJ2
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.
Read more: https://brainly.com/question/22599382
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:
https://brainly.com/question/21995826
#SPJ2
Calculate the weight of an object on earth surface having 600km from surface of earth?
Your question seems to contradict itself. You said "on Earth surface" and then you said "600 km from surface of the Earth" ... both in the same sentence.
I'll assume that the object is actually 600 km from surface of the Earth, because that makes the question (and the answer) more interesting.
We know that the weight of any object is (mass) x (gravity). Those are the two numbers we need in order to calculate the object's weight. Mysteriously, you haven't told us either one. We'll call the object's mass ' M ' (clever, eh ?), and we'll calculate the value of gravity up there where the object is located.
We now that the acceleration of gravity is inversely proportional to the square of the distance between the centers of two objects. When an object is on the Earth's surface, it's 6,371 km from Earth's center, and the acceleration of gravity there is 9.8 m/s².
The object in the question is 600 km farther from Earth's center, so the acceleration of gravity there is
(9.8 m/s²) · (6371 / 6971)² = 8.2 m/s².
So the object's weight is (8.2 M) Newtons.
This is about 84% of its weight on Earth's surface.
(Notice that the astronauts aboard the International Space Station are NOT "weightless". The strength of gravity up there where they are is around 84% of what it is down on the ground. The question of why they float, and why their muscles waste away, is a topic for another Brainly question.)
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.
A student drops two metallic objects into a 120 g steel container holding) 150 g of water at 25°C. One object is a 253 g cube of copper that is initially at 85°C, and the other is a chunk of aluminum that is initially at 5°C. To the surprise of the student, the water reaches a final temperature of 25°C, its initial temperature. What is the mass of the aluminum chunk? (please add an explanation)
Answer: 0.326kg
Explanation:
Given the following :
Mass of copper (Mc) = 253g
Initial temperature of copper (t1) = 85°C
Mass of aluminium(Ma)=?
Initial temperature of aluminum(t1) = 5°C
Specific heat capacity of aluminum(Ca) = 900
Specific heat capacity of copper (Cc) = 387
Final temperature(t2) = 5°C
Q = mc(t2 - t1)
Ma × Ca × (t2 - t1)a = Mc × Cc × (t2 - t1)c
Ma × 900 × (25 - 5) = 0.253 × 387 × (25 - 85)
Ma × 900 × 20 = 0.253 × 387 × 60
Ma × 18000 = 5874.66
Ma = 5874.66 / 18000
Ma = 0.32637
Ma = 0.326kg
The mass of the aluminum chunk dropped into the water is 325.5 g.
The given parameters;
mass of the steel, = 120 gmass of water = 150 ginitial temperature of water = 25 °Cmass of copper = 253 ginitial temperature of the copper = 85 °Cinitial temperature of the aluminum = 5 °Cfinal temperature of water = 25 °CSpecific heat capacity of aluminum = 0.9 J/gC Specific heat capacity of copper = 0.386 J/gCApply the principle of conservation of energy, the heat gained by the aluminum is equal to heat lost by the copper;
[tex]M_a C_a (t- t_a) = M_c C_c (t_c - t)\\\\M_a\times 0.9 \times (25-5) = 253 \times 0.386 \times (85-25)\\\\18 M_a = 5859.48\\\\M_a = \frac{5859.48}{18} \\\\M_a = 325 .5 \ g[/tex]
Thus, the mass of the aluminum chunk dropped into the water is 325.5 g.
Learn more here: https://brainly.com/question/20709851
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
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.
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)
A 2kg object is dropped from a height 10m.Calculate the speed of the object after it has fallen 5m, assuming there is no resistance. g= 10 N/kg
Answer:
10m/s
Explanation:
[tex]d=v_ot+\dfrac{1}{2}at^2[/tex]
Since there is no initial velocity as the object is dropped, you can write the following equation:
[tex]5=\dfrac{1}{2}(10)t^2 \\\\1=t^2 \\\\t=1[/tex]
Now that you know how long the fall took, you can use another physics equation to find the velocity at that point.
[tex]v_f=v_o+at[/tex]
Since there once again is no initial velocity, you can rewrite this as:
[tex]v_f=at=(10)(1)=10m/s[/tex]
Hope this helps!
The kinetic energy the object has at any point during the fall is exactly the potential energy it lost by falling to that height.
Potential energy = (mass) · (gravity) · (height)
Change of potential energy = (mass) · (gravity) · (change of height)
Change of potential energy = (2 kg) · (10 m/s ) · (-5 m)
Change of potential energy = 100 Joules
Kinetic energy = (1/2) · (mass) · (speed²)
Kinetic energy = (1 kg) · (speed² )
100 J = (1 kg) · (speed²)
Speed² = (100 J) / (1 kg)
Speed² = (100 kg-m²/s²) / (1 kg)
Speed² = (100 m²/s²)
Speed = 10 m/s
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
If the potential difference across the bulb in a camping lantern is 9.0 V, what is the
potential difference across the cells used to power it?
Answer:
9.0 V.
Explanation:
battery gives the voltage of 9.0 V to the lantern to use it.
The voltage across the bulb in camping lanterns is equal to the potential difference across the cells that are used to power it. So, 9 V.
What is meant by potential difference ?Potential difference between two points is defined as the amount of work required to move a unit positive charge along any path between two places in the electric field without accelerating the charge.
Here,
While the one point has a lower potential, the other one has a higher potential. The term voltage or potential difference refers to the charge difference between higher and lower potentials.
The force needed for the electrons to move through a circuit is provided by the voltage or potential difference.
In a series circuit, the voltage across a bulb is equal to the voltage across the battery only if the bulb and the battery are the only components in the circuit.
Hence,
The voltage across the bulb in camping lanterns is equal to the potential difference across the cells that are used to power it. So, 9 V.
To learn more about potential difference, click:
https://brainly.com/question/23716417
#SPJ2
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.
What is the acceleration if velocity increases from 10 m/s to 15m/s after travelling a distance of 5 metre
Answer:
a=1.25m/s²
Explanation:
GIVEN DATA
vi=10m/s
vf=15m/s
S=5m
TO FIND
a=?
SOLUTION
by using third equation of motion
2as=(vf)²-(vi)²
2a(5m)=(15m/s)²-(10m/s)²
10m×a=225m²/s²-100m²/s²
10m×a=125m²/s²
a=[tex]\frac{125}{10}[/tex]
a=12.5m/s²
A rubber band that has been stretched has gained ____ energy
OA) heat
OB) kinetic
OC) potential
D) chemical
Answer: potential
Explanation:
Which of the following is an example of Newton's Third Law of Motion?
a. a person sliding to the right as a car turns left
b. a boy pulling a sled
c. gasses pushing a rocket forward
d. a hockey puck sliding across the ice
Answer:
C. gasses pushing a rocket forward
Explanation:
A sports car accelerates from rest at 4 metre per second squared for 10 seconds , its final velocity would be?
Answer:
40m/s
Explanation:
s= NOT NEEDED
u= 0
v= ?
a=4m/s^2
t=10
find the equation
v=u+at
substitute in values:
v=0+4x10
v=40m/s
Answer:
I'm not sure
Explanation:
Because I dont
What are the eight states of matter?
Does thermal energy flow from warmer objects to cooler objects
Answer:yes
Explanation:
Thermal energy is the sum of all kinetic and potential energy in a substance. He is the thermal energy that flows from a warmer object to a cooler object.
heat is the thermal energy that flows from warmer objects to cooler objects. heat only flows one way, from warmer to cooler objects. net heat transfer ends when two objects reach the same temperature. (thermal equilibrium)
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
Help needed plz . Answer what you can. Thanx
Answer:
both a and b have same pressure
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]
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.
Why will a delivery truck filled with birds sitting on its floor be heavier than a truck with the same birds flying around inside.
The reason why a delivery truck filled with birds sitting on the floor be heavier than a truck with the same birds flying around is because when the birds are sitting on the floor, they are adding their weight to the truck.
Meanwhile, if the birds are flying around they aren't resting on the truck or touching it, so therefore their weight wouldn't be added to the truck.
The mass of the truck will remain the same as you cannot change the mass but the weight will vary depending on the items and objects placed in it.
Julie is cycling at a speed of 3.4 meters/second. If the combined mass of the bicycle and Julie is 30 kilograms, what is the kinetic energy?
A.
1.7 × 102 joules
B.
1.5 × 102 joules
C.
2.0 × 102 joules
D.
2.2 × 102 joules
Answer:
A
Explanation:
Just recall the formula for the gain in kinetic energy and substitute the values in.
calculate the frequency of a wave that is traveling at a speed of 3.0 m/s and has a wavelength of 1.2m
Answer:
2.5 Hz
Explanation:
3.0m/s / 1.2 m=2.5 1/s=2/5 Hz
The frequency of a wave with speed of 3.0 m/s and has a wavelength of 1.2m is 2.5 Hz.
What is frequency?The frequency of a wave is the number of cycles per second.
Given the wavelength is 1.2 m and speed v =3.0m/s, then the frequency of the wave is
v =fλ
f = 3 / 1.2
f = 2.5 Hz
Thus, the frequency of the wave is 2.5 Hz.
Learn more about frequency.
https://brainly.com/question/8304265
#SPJ2
explain the causes of yaa asantewaa war of 1900
Answer: the conflict began when a british representative - Sr. Frederick Mitchell Hodgson sat on the golden stool.
Explanation:
since the stool wasn't a throne, when Yaa Asantewaa found out, he led a rebellion which killed 1000 British and allied African soldiers and 2,000 Ashanti.
good luck with your assignment :)
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.
what is the wavelength of the radio waves transmitted by an FM station at 90MHz where 1M=10^6 AND THE SPEED OF RADIOWAVE IS 3*10^8m/s
Answer: 0.3m
Explanation:
Given the following :
Speed of radio wave(V) = 3 × 10^8 m/s
If 1M = 10^6
Frequency(F) = 90MHz = 90 × 10^6
Wavelength (λ) =?
Speed of wave (V) = frequency(F) × wavelength(λ)
V = fλ
(3 × 10^8) = (90 × 10^6) × λ
λ = (90 × 10^6) / (3 × 10^8)
λ = 30 × 10^(6 - 8)
λ = 30 × 10^-2
λ = 0.3m