Answer:
Explanation:
His displacement is 0 because he ended up exactly where he started.
13.Suppose a ball of mass m is thrown vertically upward with an initial speed v, its speed decreases continuously till it becomes zero. Thereafter, the ball begins to fall downward and attains the speed u again before striking the ground. It implies that the magnitude of initial and final momentums of the ball are same. Yet, it is not an example of conservation of momentum. Explain why?
Answer:
Law of conservation of momentum is applicable to isolated system (no external force is applied).
In this case, the change in velocity is due to the gravitational force of earth.When the ball is thrown up, negative force of gravity is applied and so the speed becomes zero.After that due to gravitational force the ball falls down with same initial velocity.
Connected to a battery that offers a d.d.p. of 3.0Volts, we have the four lamps, all identical with resistances equal to 2.0 Ohms. The association appears in the figure. Note that the switch is open, so it doesn't pass current in the circuit (it's like an off switch). When the key closes, the lamps come on. Determining the Req of the association and the total current flowing through the circuit, we will find:
Answer:
Option D. 5Ω e 0.6 A
Explanation:
1. Determination of the equivalent resistance.
We'll begin by calculating the equivalent resistance of resistor B and resistor C. This can be obtained as follow:
Resistor B (R₆) = 2 Ω
Resistor C (R꜀) = 2 Ω
Equivalent Resistance (R₆꜀) =?
R₆꜀ = R₆ × R꜀ / R₆ + R꜀ (parallel connection)
R₆꜀ = 2 × 2 / 2 + 2
R₆꜀ = 4 / 4
R₆꜀ = 1 Ω
Finally, we shall determine the equivalent resistance of the circuit. This can be obtained as follow:
Resistor A (Rₐ) = 2 Ω
Equivalent resistance of resistor B and C (R₆꜀) = 1 Ω
Resistor D (Rₔ) = 2 Ω
Equivalent Resistance (R) =?
R = Rₐ + R₆꜀ + Rₔ (series connection)
R = 2 + 1 + 2
R = 5 Ω
Thus, the equivalent resistance of the circuit is 5 Ω
2. Determination of the total current in the circuit.
Potential difference (V) = 3 V
Equivalent resistance (R) = 5 Ω
Total current (I) =?
V = IR
3 = I × 5
Divide both side by 5
I = 3 / 5
I = 0.6 A
Thus, the total current in the circuit is 0.6 A
Summary:
Equivalent resistance = 5 Ω
Current = 0.6 A
Option D gives the current answer to the question.
Calculate surface tension of an enlarged radius of 4cm to 6cm and amount of work necessary for enlargement was 1.5×10^-4 joules
Answer:
[tex]T=7.5*10^{-5}[/tex]
Explanation:
From the question we are told that:
Radius [tex]r=2cm[/tex]
Work done [tex]W=1.5×10^-4 joules[/tex]
Generally the equation for Work done is mathematically given by
[tex]W=T.dA[/tex]
Therefore
[tex]T=\frac{W}{dr}[/tex]
[tex]T=\frac{1.5*10^{-4}}{2}[/tex]
[tex]T=7.5*10^{-5}[/tex]
Name the physical quantity and write its SI unit which gives the slope Of I-V graph?
Slope of I-V graph is Resistance.
Its S.I. unit is Ohm.
The symbol of ohm is Ω.
Si la rapidez del sonido en el agua es de 1450 m/s. ¿Cuánto tiempo tardará en recorrer 500 m en el fondo del lago?
Answer:
2.9
Explanation:
es 2 minutos con 9 segundos seria algo así (1450)÷(500)
A ball is at the top of the hill. As the ball rolls down the hill, its total mechanical energy will:
Answer:
To explain what happens with the ball we must remember the Law of Conservation of Energy.
This law states that the energy can be neither created nor destroyed only converted from one form of energy to another.
Then,
At the top of the hill, the potential energy is maximum and the kinetic energy equals to zero.
When the ball starts to roll down the potential energy will be lower and the kinetic energy will have a low value.
At the middle of the hill, both energies have the same values.
At the end of the hill, the potential energy will be equal to zero and the kinetic energy will be maximum.
Correct me if I'm wrong...
hope it helps...
What factors could the skater change to apply the same amount of torque but increase the rate of his spin
Answer:
The moment of inertia should be decreased.
Explanation:
The torque is given by
Torque = Moment of inertia x angular velocity
To keep the torque constant, the spin rate be increased when the moment of inertia decreases.
The moment of inertia of the body are the efforts to put the object in rotation.
Atoms contain both positive nuclei and a negative electron cloud. Which of the following would cause an attraction between two atoms?
A. The nucleus of one atom and the electron cloud another atom
B.The nucleus of one atom and the nucleus of another atom
C. The electron cloud of one atom and the electron cloud of another atom
D.None of these would cause an attraction between atoms
Answer:
Option (D)
Explanation:
A. The nucleus of one atom and the electron cloud of the another atom will not the cause of attraction.
B. The nucleus of one atom and the other atom will not cause the attraction.
C. The electron cloud of one atom and the electron cloud of the another will not cause attraction.
D. So, this option is correct.
The boiling point of a substance is _72 degree Celsius. This temperature will be equivalent to Kelvin scale is-------.
Answer:
345 K
Explanation:
Temperature can be defined as a measure of the degree of coldness or hotness of a physical object.
Generally, it is measured with a thermometer and its units are Celsius (°C), Kelvin (K) and Fahrenheit (°F).
Given the following data;
Boiling point = 72°CTo convert the temperature in degree Celsius to Kelvin, we would use the following mathematical expression;
Kelvin = 273 + °C
Substituting into the formula, we have;
Kelvin = 273 + 72
Kelvin = 345 K
Therefore, the temperature of 72°C will be equivalent to 345 K on the Kelvin scale.
Which wave interaction results in a change in the direction of the wave as it passes through one medium to another medium?
Answer:
Refraction of waves involves a change in the direction of waves as they pass from one medium to another. Refraction, or the bending of the path of the waves, is accompanied by a change in speed and wavelength of the waves.
Calculate the percent error of the distanc
A space shuttle was launched from the Earth to the
moon. The average, or accepted, value of the distance
of the Earth to the moon is 238,857 miles, but the
shuttle crew recorded that their trip took 226,316 miles
5.25%
07.15%
3.75%
4.45%
Answer:
5.25%
Explanation:
From the question given above, the following data were obtained:
Accepted value = 238857 miles
Measured value = 226316 miles
Percentage error =.?
Next, we shall determine the absolute error. This can be obtained as follow:
Accepted value = 238857 miles
Measured value = 226316 miles
Absolute Error =?
Absolute Error = |Measured – Accepted|
Absolute Error = |226316 – 238857|
Absolute Error = 12541
Finally, we shall determine the percentage error. This can be obtained as follow:
Accepted value = 238857 miles
Absolute Error = 12541
Percentage error =.?
Percentage error = absolute error / accepted value × 100
Percentage error
= 12541 / 238857 × 100
= 1254100 / 238857
= 5.25%
Therefore, the percentage error is 5.25%.
A ball of mass 0.175 kg is dropped from rest from a height of 1.25 m. It rebounds from the floor to reach a height of 0.805 m. What impulse was given to the ball by the floor
Answer:
The impulse received by the ball is - 1.561 kg.m/s
Explanation:
Given;
mass of the ball, m = 0.175 kg
initial displacement of the ball, h₁ = 1.25 m
final displacement of the ball, h₂ = 0.805 m
Assumptions:
let the downward direction of the ball be positive
let the upward direction of the ball be negative
The following equation of motion will be used to determine the final velocity of the ball at each displacement.
v² = u² ± 2gh
The final velocity of the ball when it is dropped downwards to 1.25 m;
v² = u² + 2gh
v² = 0 + 2gh
v² = 2gh
v = √2gh
v = √(2 x 9.8 x 1.25)
v = 4.95 m/s
The final velocity of the ball when it rebounds from the floor to 0.805 m;
vf² = u² - 2gh
vf² = 0² - 2gh
vf² = -2gh
vf = -√2gh
vf = - √(2 x 9.8 x 0.805)
vf = -3.97 m/s
The impulse received by the ball is calculated as;
J = ΔP = mΔv = m(vf - v)
= 0.175(-3.97 - 4.95)
= - 1.561 kg.m/s
The negative sign indicates upward direction of the impulse.
If you connected 10 of these 12V (10 W) lamps in parallel, to the 12V source, how much current would the source have to supply
Answer:
[tex]T=8.33A[/tex]
Explanation:
From the question we are told that:
Number of battery [tex]n=10[/tex]
Voltage source[tex]E=12V[/tex]
Lamp Power[tex]P=10W[/tex]
Generally the equation for Resistance is mathematically given by
[tex]R=\frac{V^2}{P}[/tex]
[tex]R=\frac{12^2}{10}[/tex]
[tex]R=14.4ohms[/tex]
Therefore
[tex]R_{eq}=\frac{14.4}{10}[/tex]
[tex]R_{eq}=1.44[/tex]
Generally the equation for Current is mathematically given by
[tex]T=\ffrac{V}{Req}[/tex]
[tex]T=\frac{12}{1.44}[/tex]
[tex]T=8.33A[/tex]
What type of material does not transfer heat well?
What is the relation between acceleration due to gravity and radius of the earth?
Answer:
As the earth is an oblate spheroid, its radius near the equator is more than its radius near poles. Since for a source mass, the acceleration due to gravity is inversely proportional to the square of the radius of the earth, it varies with latitude due to the shape of the earth.
Formula: g = GM/r2
Dimensional Formula: M0L1T-2
Values of g in SI: 9.806 ms-2
Explanation:
Please Mark me brainliest
Answer:
♡
Explanation:
As the earth is an oblate spheroid, its radius near the equator is more than its radius near poles. Since for a source mass, the acceleration due to gravity is inversely proportional to the square of the radius of the earth, it varies with latitude due to the shape of the earth.
A 4 LBfweight is attached to a spring suspended from the ceiling. When the weight comes to rest at equilibrium, the spring has been stretched 3 inches. The damping constant for the system is 2 LBf−sec ft . If the weight is raised 9 inches above equilibrium and given an initial upward velocity of 2 ft/sec, determine the equation of motion of the weight and give its damping factor, quasiperiod and quasifrequency.
Answer:
attached below
Explanation:
The initial conditions :
x(0) = - 9 inches = -3/4 ft
x'(0) = - 2 ft/sec
spring stretched 3 inches = 1/4 ft
mass = w / g = 4 Ib / 32 ft/sec^2 = 1/8 slug
the spring constant ( k ) = w / l = 4 / ( 1/4 ) = 16 Ib/ft
applying the second law of motion
m d^2x/dt^2 + b dx/dt + kx
= 1/8 d^2x/dt^2 + 2 dx/dt + 16 x
= d^2x/dt^2 + 16 dx/dt + 128 x ------- ( 1 )
we will resolve the above equation to obtain the required equation of motion x( t )
Attached below is the remaining part of the solution
What must be the reaction force when someone hits a tree with an axe?
Answer: The correct option is that the axe handle applying a force to the person's hand.
Explanation:
This reaction force is due to Newton's third law of motion. This law states that for every action there is equal and opposite reaction to it. This implies that when a force is being exerted on a surface, the surface must exert a force that is equal and opposite in direction to the exerting force. This law represents a certain symmetry in nature that forces always occur in pairs, and one body cannot exert a force on another without experiencing a force itself.
A typical example of Newton's third law includes:
--> When you hit a tree with an axe: with your hand you exert a force on the tree with the intention to cut it down(action force). The same force you excreted on the tree would be felt in your hands (reaction force).
--> when air rushes out of a balloon: when air escapes for a balloon, the opposite reaction is that the balloon flies up.
[tex]what \: is \: mirror \: {?}[/tex]
Answer the question plz
Answer:
b and d
Explanation:
how long will it take a car to go from 0 to 45 km/hr if they are accelerating at 5 km/hr/s?
Answer:
9 seconds
Explanation:
[tex]acceleration = \frac{final \: speed - initial \: speed}{time \: taken} [/tex]
[tex]5km/ hr/ s = \frac{45 - 0 (km/ h)}{t} [/tex]
cross multiplying
[tex]5t = 45 secs \\ t = 9 \: secs[/tex]
it will take 9secs for the car to go from 0 to 45 km/ h
Liquid to solid with explanation on the basis of kinetic model and freezing point.
Answer:
As a liquid is cooled its molecules lose kinetic energy and their motion slows. When they've slowed to where intermolecular attractive forces exceed the collisional forces from random motion, then a phase transition from liquid to solid state takes place and the material freezes.
hope this helps you..!!!!3.00 m^3 of water is at 20.0°C.
If you raise its temperature to
60.0°C, by how much will its
volume expand?
Water
ß = 207•10-6C-1
(Unit = m^3)
Answer:
9m^3
Explanation:
Given data
volume v1= 3m^3
volume v2= ???
Temperature T1= 20.0°C.
Temperature T2= 60.0°C.
Applying the relation for temperature and volume
V1/T1= V2/T2
substitute
3/20= V2/60
3*60= V2*20
180= 20*V2
180/20= V2
V2= 9m^3
Hence the final volume is 9m^3
Give reason:
Mass and volume are called physical quantities.
a.
b
Ionath is called
Mass and volume are called physical quantities because they can be measured by using physical devices i.e. mass is measured by using beam balance and volume is measured by using metre scale .
A body of mass 8000 moving with a velocity of 2.5m/s collides with a stationery twice the mass of the first body. After impact the mass moves to 1.0m/s Find the speed of the first body.
Answer:
the final speed of the first ball is 0.5 m/s
Explanation:
Given;
mass of the first body, m₁ = 8000 kg
mass of the second body, m₂ = 16,000 kg
initial velocity of the first body, u₁ = 2.5 m/s
initial velocity of the second body, u₂ = 0
final velocity of the stationary mass, v₂ = 1 m/s
let the final velocity of the first body = v₁
Apply the principle of conservation of linear momentum;
m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂
8000(2.5) + (16,000 x 0) = 8000v₁ + 16,000 (1)
20,000 + 0 = 8000v₁ + 16,000
8000v₁ = 4000
v₁ = 4000/8000
v₁ = 0.5 m/s
Therefore, the final speed of the first ball is 0.5 m/s
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26. D. crushing the sugar cube and dissolving it in water.
27. A. atom
28. B. molecule
29. B. plum pudding model of Joseph John Thomson
30. B. He used cathode ray tubes which showed that all atoms contain tiny negatively charged subatomic particles or electrons.
31. D. protons and neutrons are relatively heavier than electrons.
If a car drives 10 mph South, this is an example of a:
A. Displacement
B. Velocity
C. Distance
D. Speed
If a car drives 10 mph South, this is an example of a:
If a car drives 10 mph South, this is an example of a: Displacement
[DISPLACEMENT IS THE SHORT DISTANCE TRAVELLED BY A BODY AT A CERTAIN DIRECTION]
A velocity would be an automobile traveling south at 10 mph. Option B is correct.
What is velocity?The change of displacement with respect to time is defined as velocity. velocity is a vector quantity. It is a time-based component. Its unit is m/sec.
If the direction is given quantity is a vector quantity. In the given data the direction is given, that's why a car drives 10 mph South, this is an example of a velocity.
Hence, option B is correct.
To learn more about the velocity, refer to the link: https://brainly.com/question/862972
#SPJ2
a body is moving along a circular path 'r'. what will be the distance and displacement of the body when it completed half a revolution?
After half of a revolution ...
==> Distance = π•r
==> Displacement = 2•r
State any ten reasons why students in Uganda need to study physics.(use examples of the possible technological advancements which can be made using the knowledge of physics)
Answer:
The answer is "physics ".
Explanation:
Physics is the branch of science that addresses the properties of crystalline and its interaction with the fundamental elements of the universe. It covers subjects ranging in quantum mechanics with extremely little ones with quantum mechanics to the whole cosmos. You must be constant whether you like it or not, thus everyone must learn physics, irrespective of whether they're in Uganda, and plenty of other countries should have physics to dare study.
The weight of a body is 600 N. What is the mass of the body on the surface of the earth?
Explanation:
soln,
weight=600N
mass=?
gravity=9.8 m/s²
now,
mass=weight/gravitymass=600/9.8mass=61.22kghope it helps.
stay safe healthy and happy.Answer:
m = 61.22 kg
Explanation:
F = 600 N
g = 9.8 m/s²
m = ?
F = mg
600 = m(9.8)
---> m = 61.22 kg
If no braking occurs, a total of how much power would be required to keep the railcar moving at 40 m/s
Answer:
40 kW
Explanation:
A railcar has a continuous 1000 N decelerating force any time it is in motion. If no braking occurs, how much power would be required to keep the railcar moving at 40 m/s
Solution:
Power in Physics is the rate of doing work and the work can be mechanical, electrical, etc. The S.I unit of power is the watts (W).
The power required to keep the car moving must match the work done by the friction force (decelerating force) that tends to slow down the railcar.
Work done = Force * displacement
Power = Work done / time = (Force * displacement) / time
Power = Force * (displacement / time)
Power = force * velocity = 1000 N * 40 m/s = 40000 W
Power = 40 kW
