Answer:
second is the SI unit of time
Kevin used a pulley to lift a piano to the third floor of his apartment. His input work was 12,000 J and the output work was 10,000 J. What was the mechanical efficiency of the pulley?
A . 50%
B. 83.3%
C . 120%
D. 16.7%
Answer:
B
Explanation:
Eff = output work/input work ×100
Hence, Eff = 10000/12000 × 100
Eff = 83.3%
A small emergency generator supplies 432 000 000 J of electrical energy in twenty-four hours. What is the average power output of the generator?
Answer:
P = 5 kW
Explanation:
Given that,
Electrical energy = 432 000 000 J
Time, t = 24 h = 86400 s
We need to find the power output of the generator. We know that,
Power = work done/time
So,
[tex]P=\dfrac{432 000 000}{86400}\\\\P=5000\ W[/tex]
or
P = 5 kW
So, the power output of the generator is 5 kW.
16 100 g of water at 25 °C is poured into an insulating cup. 50 g of ice at 0 °C is added to the water.
The water is stirred until the temperature of the water has fallen to 0°C.
18 g of ice remains unmelted.
The specific heat capacity of water is 4.2 J /g °C.
Which value does this experiment give for the specific latent heat of fusion of ice?
Answer:
Q = Q
mcT = ml
100 x 4.2 x 25 = (50-18) l
l = 328
*Hope it helps*
The specific latent heat of fusion of the melted ice is 328.13 J/kg.
Conservation of energy
The specific latent heat of fusion of the melted ice is determined by applying the principle of conservation of energy as shown below;
Heat lost by the water = Heat gained by the ice
McΔθ = mL
where;
c is specific heat capacity of waterL is pecific latent heat of fusion of icem is mass of melted ice = 50 g - 18 g = 32 g(100)(4.2)(25) = (32)L
32L = 10500
L = 328.13 J/kg
Thus, the specific latent heat of fusion of the melted ice is 328.13 J/kg.
Learn more about heat capacity here: https://brainly.com/question/16559442
A wire, 20m long, is heated from a temperature of 5°C to 55°C. If the change in length is 0.020m, calculate the linear expansivity of the wire.
Answer:
0.01998⁰C;¹
Explanation:
you can see all steps in photo
The primary circuit of a transformer has a voltage of 80 V and 300 windings. The secondary circuit has a voltage of 240. How many windings are there in the secondary circuit? *
Answer:
900 windings
Explanation:
Applying,
Vs/Vp = Ns/Np............. Equation 1
Where Vs = Secondary voltage, Vp = primary voltage, Ns = Number of turns in the secondary circuit, Np = number of turns in the primary circuit
make Ns the subject of the equation
Ns = VsNp/Vp........... Equation 2
From the question,
Given: Vs = 240 V, Np = 300 windings, Vp = 80 V
Substitute these values into equation 2
Ns = (240×300)/80
Ns = 900 windings
A car moves 20 km towards the North and then 35 km at an angle of 60o towards west of North. Its magnitude of displacement from the initial position will be
Answer:
15
Explanation:
displacement = initial position - final position
25)Two forces are acting on a block in opposite directions as shown in the figure above
(a) Calculate the net force acting on the block.
(b) In which direction will the net force tend to move the object?
(c) Will any other force try to oppose the motion of the block?
[tex]\boxed{ \sf{Answer}} [/tex]
____________________
(a) A = 5 kgwt
B = 10 N
First convert 5 kgwt to N,
[tex]5 \times 9.8 \\ = 49 \: N[/tex]
Net force [the forces are acting in 2 opposite directions]
[tex]A - B \: \\ = 49 - 10 \\ = 39 \: N[/tex]
____________________
(b) Since, the force is greater by A ↦the block will move towards B, i.e, to the right.
____________________
(c) Frictional force will try to oppose the motion of the block but since A has greater force than B, the frictional force will be resisted.
____________________
ʰᵒᵖᵉ ⁱᵗ ʰᵉˡᵖˢ ツ
꧁❣ ʀᴀɪɴʙᴏᴡˢᵃˡᵗ2²2² ࿐
why solid keep their shape?
Answer:
Solids can hold their shape because their molecules are tightly packed together. ... Atoms and molecules in liquids and gases are bouncing and floating around, free to move where they want. The molecules in a solid are stuck in a specific structure or arrangement of atoms
Hope this helps ☆*:. o(≧▽≦)o .:*☆
un litro de un gas es calentado a presión constante desde 20°C hasta 60°C que volumen final ocupará dicho gas?
Answer:
Final volume, V2 = 3 Litres
Explanation:
Given the following data;
Initial volume, V1 = 1 litre
Initial temperature, T1 = 20°C
Final temperature, T2 = 60°C
To find the final volume, we would use Charles' law;
Charles states that when the pressure of an ideal gas is kept constant, the volume of the gas is directly proportional to the absolute temperature of the gas.
Mathematically, Charles is given by;
V1/T1 = V2/T2
Making V2 as the subject formula, we have;
V1T2 = V2T1
V2 = (V1T2)/T1
Substituting into the formula, we have;
V2 = (1 * 60)/20
V2 = 60/20
Final volume, V2 = 3 Litres
A stone is thrown vertically upwards with an initial velocity of 20m/sec. Find the maximum height ot reaches and the time taken by it to reach the height. (g=10m/s2)
plz short numerical ASAP
Answer:
The height reached is 20m, The time taken to reach 20m is 2 seconds
Explanation:
Observing the equations of motion we can see that the following equation will be most helpful for this question.
[tex]v^{2} = u^{2} + 2as[/tex]
We are given initial velocity, u
We know that the stone will stop at its maximum height, so final velocity, v
Acceleration, a
And we are looking for the displacement (height reached), s
Substitute the values we are given into the equation
[tex]0^{2} = 20^{2} + 2(10)s[/tex]
Rearrange for s
[tex]0^{2} -20^{2} =20s[/tex]
[tex]-400=20s[/tex]
[tex]\frac{-400}{20} =s[/tex]
s = -20 (The negative is just showing direction, it can be ignored for now)
The height reached is 20m
Use a different equation to find the time taken
[tex]s = vt - \frac{1}{2} at^{2}[/tex]
Substitute in the values we have
[tex]-20=(0)t - \frac{1}{2} (10)t^{2}[/tex]
Rearrange for t
[tex]-20 =0 -5 t^{2}[/tex]
[tex]\frac{-20}{-5} =t^{2}[/tex]
[tex]4 = t^{2}[/tex]
t = 2s
The time taken to reach 20m is 2 seconds
why physics ought to be studied?
Answer:
The goal of physics is to understand how things work from first principles. ... Courses in physics reveal the mathematical beauty of the universe at scales ranging from subatomic to cosmological. Studying physics strengthens quantitative reasoning and problem solving skills that are valuable in areas beyond physics.
A 20-N force acts on a 5-kg object at rest. How fast will
the object accelerate on a frictionless surface?
A. 15 m/s^2
B. 25 m/s^2
C. 4 m/s^2
D. 100 m/s^2
Answer:
C.
Explanation:
Force = Mass * Acceleration
So 20 = 5* Acceleration
4 = Acceleration
The acceleration of the object is 4 m/s².
To find the acceleration, the given values are:
Force = 20 N
Mass = 5 kg
Define acceleration.Definition:
As it was given as the values of Force and mass, here acceleration definition depends on the Newton's second law of motion.
Using the second law of motion, the force will be equal to the product of the mass and the acceleration.
As formula,
F = ma Newton
Here, to find acceleration,
a =f/ m
Substituting the values,
= 20 / 5
a = 4m/s².
So, the acceleration was 4 m/s². The Option C is the correct answer.
Learn more about acceleration,
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Cual es el deporte que le da fortaleza y flexibilidad al cuerpo
Answer:
Aesthetic sports
Explanation:
Aesthetic sports are the one's that need well-developed physical qualities such as strength, agility, stamina, flexibility, and technical knowledge and artistry, in addition to technical ability and artistry. Elite athletes in these sports generally have a low abdominal fat , and the ranking is subjective.
In aesthetic sports like gymnastics, swimming, and figure skaters, dynamic and proactive flexibility is required.
newtons second law lab report link
Answer:
ghittu iihg उह्स उउह्स उग्य्किव जिक्ह्ब
Light of wavelength 530.00 nm is incident normally on a diffraction grating, and the first‑order maximum is observed to be 33.0∘ from the normal. How many slits per millimeter are marked on the grating?
Answer:
1028 slits/mm
Explanation:
We are given that
Wavelength of light, [tex]\lambda=530nm=530\times 10^{-9} m[/tex]
1nm=[tex]10^{-9} m[/tex]
[tex]\theta=33^{\circ}[/tex]
n=1
We have to find the number of slits per mm are marked on the grating.
We know that
[tex]dsin\theta=n\lambda[/tex]
Using the formula
[tex]dsin33^{\circ}=1\times 530\times 10^{-9}[/tex]
[tex]d=\frac{530\times 10^{-9}}{sin33^{\circ}}[/tex]
[tex]d=9.731\times 10^{-7} m[/tex]
1m=[tex]10^{3}mm[/tex]
[tex]d=9.731\times 10^{-7}\times 10^3[/tex]mm
[tex]d=0.0009731mm[/tex]
Number of slits=[tex]\frac{1}{d}[/tex]
Number of slits=[tex]\frac{1}{0.0009731}[/tex]/mm
Number of slits=1028/mm
Hence, 1028 slits/mm are marked on the grating.
Answer:
1027.6 lines per mm.
Explanation:
wavelength = 530 nm
order, m= 1
Angle = 33 degree
Let the slits per mm is 1/d.
So,
[tex]m \lambda = d sin A\\\\1\times 530\times 10^{-6} = d sin 33\\\\\frac{1}{d} = 1027.6 lines per mm[/tex]
is the answer correct or wrong
Answer:
wrong answer because m=100
Explanation:
I think it is incorrect
Ah, I tried
A convex mirror of radius of curvature 1.6 m has an object placed at a distance of 1.0 m from it. Find the position of image and the magnification.
Answer:
The image is formed at 0.44 m in front of the mirror
magnification (M) = 0.44
Explanation:
Applying, mirror formular
1/f = (1/u)+(1/v).................... Equation 1
Where f = Focal length of the convex mirror, u = object distance, v = image distance.
Using the real is positive convection,
From the question,
Given: f = -1.6/2 = -0.8 m( The focal length of a convex mirror is vitual), u = 1.0 m
Substitute these values into equation 1
-1/0.8 = (1/v)+(1/1)
Solve for v
1/v = 1.25+1
1/v = 2.25
v = 1/2.25
v = 0.44 m
Hence the image is formed at 0.44 m in front of the mirror
Magnification (M) = v/u
m = 0.44/1
m = 0.44
A sample of nitrogen gas is inside a sealed container. The volume of the container decreases while the temperature is kept constant. This is a ________ process.
a) isothermal
b) constant-volume
c) adiabatic
d) isobaric
An object is free falling near the surface of the earth. At a certain instant in time, it is falling downward at a rate 25.0 m/s. After 2.5 seconds, what are its acceleration and velocity?
Answers:
acceleration = 9.81 m/s^2velocity = 49.5 m/sThe values are approximate.
==========================================================
Explanation:
When near the surface of the earth, the acceleration of gravity is roughly 9.81 m/s^2. This means that after each second passes, the velocity increases by roughly 9.81 m/s.
After 2.5 seconds, the velocity increases by 2.5*9.81 = 24.525 m/s = 24.5 m/s
If it was already going 25.0 m/s, then it bumps up to 25.0+24.5 = 49.5 m/s which is also approximate.
The acceleration of gravity stays the same when the object is close to the surface of the earth, so it stays at roughly 9.81 m/s^2
Side note: I'm ignoring air resistance (aka air friction or drag) since that greatly complicates things, and we would need to know the shape and surface area of the object. The material type would also be relevant info as well.
what do you mean by supplementary quantities and its unit?
$ \large\boxed{ \sf \red{More ~Info :}}$
The units of supplementary quantities are dimensionless units.
[tex] \\ [/tex]
the direction of applied force has to be_____ to the distance in order to say work is done
Answer:
Explanation:
The direction of the applied force has to be parallel to the distance an object moved in order to say that work has been done.
A blue line with 5 orange tick marks then one red tick mark then 4 orange tick marks. The number zero is above the red tick mark.Assume each tick mark represents 1 cm.Calculate the total displacement from 0 if an object moves 3 cm to the left, then 7 cm to the right, and then 6 cm to the left.The object moves cm to the left.What is the total distance the object travels? cm
Answer:
16 cm
Explanation:
Given that,
The object begins from 0 and moves 3cm towards left side followed by 7 cm towards the right and then, 6 cm towards the left side.
Let the x-axis to be the +ve and on the right side and -ve on the left
Thus, displacement would be:
= 0 -3 + 7 -6
= -2 cm
This implies that the object displaces 2cm towards the left.
While the total distance covered by the object equal to,
= 0cm + 3cm + 7cm + 6cm
= 16 cm
Thus, 16 cm is the total distance.
Answer:
Its 2 to the right
Explanation:
edge :p
what is the effect of pressure on boiling and melting substance?
Answer:
The boiling point of liquids always increases when pressure is applied on a liquid. This is because the molecules of a liquid will need more energy to turn into a gaseous state when pressure is applied on that substance.
A basketball is shot by a player at a height of 2.0 m. The initial angle
was 53° above horizontal. At the highest point the ball was travelling 6
m/s. If he scored (the ball went through the rim that is 3.00 m above the
ground), what was the player’s horizontal distance from the basket?
Answer:
The answer is "8.28 m".
Explanation:
[tex]\to u \cos 53^{\circ}=6 \ \text{therefore the horizontal velocity is constant alaways}\\\\\therefore[/tex]
[tex]u= \frac{6 \times 5}{3}= \frac{30}{3}= 10\ \frac{m}{s}\\\\[/tex]
In the projectfile when vertical displacement is 1 then 5 m comes at farther sides
Using
[tex]S=ut-\frac{1}{2} gt^2\\\\1=u\sin 53^{\circ}\times t-5t^2\\\\1=8t-5t^2\\\\5t^2-8t+1=0\\\\ t=\frac{8\pm \sqrt{64-20}}{10} \\\\=\frac{8\pm 2\sqrt{11}}{10} \\\\t_2=\frac{8+2\sqrt{11}}{10} \\\\[/tex]
[tex]Distance=u \cos 53^{\circ}\times t_2\\\\[/tex]
[tex]=6 \times \frac{8\pm 2\sqrt{11}}{10} \\\\=\frac{24\pm 6\sqrt{11}}{5} \\\\= 8.28 \ m[/tex]
What is the difference between heat capacity and specific heat capacity? I want the meaning please.
Answer:
The heat capacity of a body is defined as the heat required to raise it's temperature by me degree or one kelvin.while specific heat capacity of a substance is defined as the heat required to the temperature of a unit mass of it through one degree or one kelvin.
I hope it helps
A vector points -43.0 units along the x axis, and 11.1 units along the y axis. Find the Direction of the vector.
Answer:
Explanation:
The direction of the vector implies only its angle, not its magnitude. The direction of the vector is found in
[tex]tan^{-1}(\frac{y}{x})[/tex] so
[tex]tan^{-1}(\frac{11.1}{-43.0})=-14.5[/tex] but since we are in QII (where x is negative and y is positive) we have to add 180 to this number to get a direction of 165.5 degrees
The Indianapolis speedway consists of a 2.5 mile track having four turns, each 0.25 mile long and banked at 9 12'
Answer: Your question is missing below is the question
Question : What is the no-friction needed speed (in m/s ) for these turns?
answer:
20.1 m/s
Explanation:
2.5 mile track
number of turns = 4
length of each turn = 0.25 mile
banked at 9 12'
Determine the no-friction needed speed
First step : calculate the value of R
2πR / 4 = πR / 2
note : πR / 2 = 0.25 mile
∴ R = ( 0.25 * 2 ) / π
= 0.159 mile ≈ 256 m
Finally no-friction needed speed
tan θ = v^2 / gR
∴ v^2 = gR * tan θ
v = √9.81 * 256 * tan(9.2°) = 20.1 m/s
20 kg rodsis on the edge of a 80 m high de What is the rodes gracional potencial energy?
Answer:
Gpe = 15680 Joules
Explanation:
Gravitational potential energy (GPE) is an energy possessed by an object or body due to its position above the earth.
Mathematically, gravitational potential energy is given by the formula;
G.P.E = mgh
Where;
G.P.E represents potential energy measured in Joules.
m represents the mass of an object.
g represents acceleration due to gravity measured in meters per seconds square.
h represents the height measured in meters.
Given the following data;
Mass = 20 kg
Height = 80 m
We know that acceleration due to gravity is equal to 9.8 m/s²
To find the gravitational potential energy;
Gpe = mgh
Gpe = 20 * 80 * 9.8
Gpe = 15680 Joules
An electron experiences a downward force of 12.8×10-19 N while traveling in a magnetic field of 8×10-5 T west, what is the magnitude of the velocity?
Answer:
[tex]v=10^5\ m/s[/tex]
Explanation:
Given that,
Magnetic force acting on an electron, [tex]F=12.8\times 10^{-19}\ N[/tex]
The magnitude of the magnetic field,[tex]B=8\times 10^{-5}\ T[/tex]
We need to find the magnitude of the velocity. We know that the magnetic force is given by :
[tex]F=qvB[/tex]
Where
v is the velocity
So,
[tex]v=\dfrac{F}{qB}\\\\v=\dfrac{12.8\times 10^{-19}}{1.6\times 10^{-19}\times 8\times 10^{-5}}\\\\v=10^5\ m/s[/tex]
So, the magnitude of velocity is[tex]10^5\ m/s[/tex].
How would you find the resistance of a parallel circuit with n identical resistors?
9514 1404 393
Answer:
R/n
Explanation:
For a given voltage V across each resistor R, the current is V/R. Since there are n parallel paths, the total current is n(V/R). The effective resistance is ...
Reff = V/I = V/(nV/R)
Reff = R/n
