Answer:
Given information:-
Radius of the circular track is 636 mThe time elapsed in the journey is 1.5 min or 90 sThe distance traveled by the cyclist is semi circumference of the circle = πr[tex]\clubsuit[/tex]The displacement of the cyclist will be shortest distance from his initial to final positions which is nothing but diameter of the circle = 2r
We know that,
[tex] \underline{ \boxed{ \sf{Speed = \frac{Distance \: covered }{Time \: taken}}}}[/tex]
[tex]\longrightarrow \sf{\frac{636 \times 3.14 m}{90s}} \\ \\ \longrightarrow \sf22.18 m/s[/tex]
Speed of the cyclist is 22.18 m/s[tex]\sf{Velocity = \frac{Displacement }{ Time} }[/tex]
[tex]\longrightarrow \sf{ \frac{2 \times 636m}{90s} } \\ \\ \longrightarrow \sf{14.13 \: m/s}[/tex]
Velocity of the cyclist is 14.13 m/sThank You :)
please answer these diagrammatic questions ASAP and please no spam answers
Answer:
i. The pressure of due to the water, P, is given according to the following equation;
P = ρ·g·h
Where;
ρ = The density of the water (a constant) = 997 kg/m³
g = The acceleration due to gravity = 9.81 m/s²
h = The height of the water (minimum h = h₁, maximum h = h₂)
The pressure is directly proportional to the water height, and we have;
The pressure, P, will be maximum when the water height, h, is maximum or h = h₂, which is the level DC
ii. The thrust = The force acting on the body = Pressure × Area
The maximum areas exposed to the water are on side AB and DC
However, the pressure at level DC, which is the location of the maximum pressure, is larger than the pressure at level AB, therefore, the maximum thrust will be at the level DC
Explanation:
use the particle model to explain why the water expands
Answer:
Take water as an example; the size, shape and chemical composition of the water particles remains the same whether it is solid water (ice) or gaseous water (steam) - but how those particles move and are arranged is different for
if you add km/ hr with another km/ hr what will you get
Answer:
km/hr
Explanation:
Addition and subtraction are commutative
Meaning you can add or subtract in any order because it doesn't change the sum or the difference. So it doesn't change the units.
Answer:
km/ hr + km/ hr =(km+ km)/hr=2km/hr
Explanation:
A force of 15N acts on an area of 60m².What is the pressure? *
Answer:
0.25p.a
Explanation:
force=15N area=60m²
so pressure =force/area =15N/60m²=0.25p.a
a body of radius R and mass m is rolling horizontally without slipping with speed v. it then rolls us a hill to a maximum height h=3v2/4g
Answer:
mR²/2
Explanation:
Here is the complete question
An object of radius′
R′ and mass ′
M′ is rolling horizontally without slipping with speed ′
V′
. It then rolls up the hill to a maximum height h = 3v²/4g. The moment of inertia of the object is (g= acceleration due to gravity)
Solution
Since it rolls without slipping, there is no friction. So, its initial mechanical energy at the horizontal surface equals its final mechanical energy at the top of the hill.
Since the object is rolling initially, and on horizontal ground, it initial energy is kinetic and made up of rotational and translational kinetic energy.
So, E = K + K'
E = 1/2mv² + 1/2Iω² where m = mass of object, v = speed of object, I = moment of inertia of object and ω = angular speed of object = v/r where v = speed of object and R = radius of object.
Also, the final mechanical energy of the object, E' is its potential energy at the top of the hill. So, E' = mgh.
Since E = E',
1/2mv² + 1/2Iω² = mgh
substituting the values of ω and h into the equation, we have
1/2mv² + 1/2Iω² = mgh
1/2mv² + 1/2I(v/R)²= mg(3v²/4g)
Expanding the brackets, we have
1/2mv² + 1/2Iv²/R²= 3mv²/4
Dividing through by v², we have
1/2m + I/2R²= 3m/4
Subtracting m/2 from both sides, we have
I/2R² = 3m/4 - m/2
Simplifying, we have
I/2R² = m/4
Multiplying through by 2R², we have
I = m/4 × 2R²
I = mR²/2
Lúc 7g bạn an đi từ nhà đến trường với tóc độ trung bình là 20km/h . Bạn đến trường lúc 7g20. Tính khoảng cách từ nhà tới trường?
Answer:
Distance = 6.667 kilometres
Explanation:
Given the following data;
Speed = 20 km/h
Departure time = 7:00
Arrival time = 7:20
Time taken = 20 minutes
To calculate the distance travelled from home to school;
First of all, we would have to convert the value of time in minutes to hours.
Conversion:
60 minutes = 1 hour
20 minutes = X hours
Cross-multiplying, we have;
X = 20/60 = 1/3 hours
Mathematically, the distance travelled by an object is calculated by using the formula;
Distance = speed * time
Distance = 20 * 1/3
Distance = 20/3 =
Distance = 6.667 kilometres
A train 90m long stops in a train station with its front buffers in line with a lamp post on the platform. Later it starts off with an average acceleration of 0.45m/s. What will be its speed in kilometers per hour when the tail buffers pass the lamp post P?
Answer:
The speed of the train when the tail buffers pass the lamp post is 9 m/s
Explanation:
The given parameters are;
The length of the train = 90 m
The initial velocity of the train, u = 0
The average acceleration of the train, a = 0.45 m/s²
When the tail buffer pass the lamp post, P, we have;
The distance travelled, s = The length of the train = 90 m
The kinematic equation of motion is given as follows;
v² = u² + 2·a·s
Where;
v = The speed of the train when the tail buffers pass the lamp post
∴ v² = 0² + 2 × 0.45 m/s² × 90 m = 81 m²/s²
Therefore;
v = √(81 m²/s²) = 9 m/s
The speed of the train when the tail buffers pass the lamp post, v = 9 m/s.
is noise energy a kind of energy or not
A tray containing 0.20kg of water at 20degree celsius is placed in a freezer. The temperature of the water drops to 0degree celsius in 10 minutes. Calculate
a) The energy lost by the water asit cools to 0 degree celsius.
b) The average rate at which the water is losing energy in J/s.
c) Estimate the time taken for the water at 0 degree celsius to turn completely into ice.
d) state any assumptios you make
Answer:
a. Energy lost, Q = 16,800 Joules.
b. Power = 28 J/s
c. Time, t = 2357.14 seconds
d. I assumed that the ice remained at a temperature of zero degrees Celsius (0°C). Also, I assumed that the heat is being lost at a constant rate.
Explanation:
Given the following data;
Mass = 0.20 kgInitial temperature, T1 = 20°CFinal temperature = 0°CTime = 10 minutesa. To find the energy lost by the water as it cools to 0 degree celsius;
Mathematically, heat capacity is given by the formula;
[tex] Q = mcdt [/tex]
Where;
Q represents the heat capacity or quantity of heat.M represents the mass of an object.C represents the specific heat capacity of water.dt represents the change in temperature.dt = T2 - T1
dt = 20 - 0
dt = 20°C
We know that the specific heat capacity of water is equal to 4200 J/kg°C
Substituting the values into the formula, we have;
[tex] Q = 0.20 * 4200 * 20 [/tex]
Energy lost, Q = 16,800 Joules.
b. To find the average rate at which the water is losing energy in J/s by using the following formula;
[tex] Power = \frac {energy}{time} [/tex]
First of all, we would have to convert the value of time in minutes to seconds.
Conversion:
1 minute = 60 seconds
10 minutes = X seconds
Cross-multiplying, we have;
X = 60 * 10
X = 600 seconds
Substituting the values into the formula, we have;
[tex] Power = \frac {16800}{600} [/tex]
Power = 28 J/s
c. To estimate the time taken for the water at 0 degree celsius to turn completely into ice;
We know that the latent heat of fusion of water is equal to 3.3 * 10⁵ J/kg.
Mathematically, the latent heat of fusion is calculated by using the formula;
Energy, Q = ml = pt
Substituting the values into the formula, we have;
0.20 * 3.3 * 10⁵ = 28 * t
0.20 * 330000 = 28t
66000 = 28t
[tex] t = \frac {66000}{28} [/tex]
Time, t = 2357.14 seconds.
d. The assumption made is that, the ice remained at a temperature of zero degrees Celsius (0°C). Also, I assumed that the heat is being lost at a constant rate.
A motorcycle is moving at a constant velocity of 15 meters/second. Then it starts to accelerate and reaches a velocity of 24 meters/second in 3 seconds. What’s the acceleration of the motorcycle over this time? Use .
A.
9 m/s2
B.
8 m/s2
C.
6 m/s2
D.
5 m/s2
E.
3 m/s2
option E
3m/s square
hope it helped u
Examine the motion map. One animal is an antelope that is already running. The other is a cheetah that starts running after the antelope passes it. Does A or B represent the motion of the cheetah?
Answer:
A although am not seeing the cheetah
Why is velocity proportial to pressure?
Answer:
Pressure and velocity are inversely proportional to each other because if pressure increase, the velocity decrease to keep the algebraic sum of potential energy, kinetic energy and pressure constant.
What did Ernest Rutherford's experiment of a beam of alpha particles aimed
at a sheet of gold foil lead him to conclude?
A. The theory that atoms were the building block of all matter was
correct.
B. The majority of the atom's mass and its positive charge are
concentrated in the atom's center.
C. An electron has a larger mass than the alpha particles, causing
them to reflect upon collision.
D. J.J. Thomson's theory of electrons suspended in a sea of
positively charged particles was correct.
Answer:
B - Only a concentration of mass in the nucleus could explain the deflection of the incident particles.
A race car sits on the starting line on a racetrack. when the race starts, the car's tires exert a force on the track. According to newton's third law of motion, what causes the car to accelerate forward?
A. the track surface exerts a force that is larger and in the same direction as the force exerted by th tires.
B. a normal force that is equal in a magnitude to gravity pushes up on the car
C. the force of friction between the car tires and the track pulls the car forward
D. the track exerts a force that is equal and in the opposite direction as the force exerted by the tires
Answer:
D. the track exerts a force that is equal and in the opposite direction as the force exerted by the tires
Explanation:
Newton's third law of motion states that for every action, there is an equal and opposite reaction. This speaks of equality in magnitude of force applied but in an opposite direction to one another.
According to this reaction, a car's tires exert a force on the track, this means that in accordance to Newton's third law, the track must exert an equal but opposite force on the car's tires. This causes the car to accelerate forward.
Using your Periodic Table, which of the elements below is most likely to be a solid at room temperature?
A.) potassium, B.) Hydrogen, C.) Neon, D.) Chlorine
The answer is definitely Potassium
When should a line graph be used?
A. When the independent variable is continuous and shows a causal link to the dependent variable.
B. When the independent variable is composed of categories and does not show a relationship.
C. When there is no independent variable.
D. When the independent variable is continuous and does not show a relationship to the dependent variable.
Answer:
A. When the independent variable is continuous and shows a causal link to the dependent variable.
Explanation:
A graph can be defined as the graphical representation of data (informations) on horizontal and vertical lines i.e x-axis and y-axis respectively.
In an experiment , the variable being manipulated by an experimenter is known as an independent variable while the dependent variable is the event expected to change when the independent variable is manipulated
Generally, a line graph should be used when the independent variable is continuous and shows a causal link to the dependent variable.
This ultimately implies that, a line graph should be used when the data changes continuously over time and as such there exist a linear relationship between the data (variables).
write down any 5 example of conservation of momentum?
Answer:
1) Motion of air mass moving from equator northward (closer to earth axis)
2) Motion of object in orbit
3) Collision of 2 objects
4) Skater changing rotation by extension of arms
5) Motion of rocket due to velocity of expelled gas
Ella wants to replace old bulbs of her home with new LED bulbs. She buys LED bulb that has inbuilt AC to DC converter of output 5 v and 2.5 A. If the LED is 75% efficient, what would be power dissipated? Also find work done by LED when it is connected to power supply and left for 1 hr 15 minutes?
Answer:
Power = I * V = 2.5 C/s * 5 J/C = 12.5 J/s = 12.5 watts
Regardless of the efficiency the power consumed is that used by the converter.
E = P * t = 12.5 J/s * 4500 s = 4500 J
You observe that you see more mockingbirds in small trees and more hawks in large trees. Which of the following is an appropriate scientific question based on this observation?
How does the size of a tree affect the bird species that prefer to live in it?
How do birds fly?
What type of food do birds eat?
What time of year to birds mate?
Answer:
A) How the size of a tree affect the bird species that prefer to live in it
Explanation:
I took the quiz
any correct ans guess for 30 pts and brainlist
Answer:
a) ii
b) i
c)iii
d)iii
e) i
f)iii
Explanation:
i hope this will help
Answer:
the answer of b is N and d is mol
How does the electric field intensity vary with the increase of distance of the point from the centre of a charged conducting sphere? Explain with graph.
Answer:
(i) Electric field outside the shell:
For point r>R; draw a spherical gaussian surface of radius r.
Using gauss law, ∮E.ds=q0qend
Since E is perpendicular to gaussian surface, angle betwee E is 0.
Also E being constant, can be taken out of integral.
So, E(4πr2)=q0q
So, E=4πε01r2q
explain why resistors connected in parallel are called current dividers
Explanation:
A parallel circuit is often called a current divider for its ability to proportion—or divide—the total current into fractional parts. Once again, it should be apparent that the current through each resistor is related to its resistance, given that the voltage across all resistors is the same
Help quick
How does the ramp produce mechanical advantage?
A it reduces the amount of input force needed to do a certain amount of work
B it reduces the distance over which the input force needs to be applied
C it reduces the amount of useful work done on objects move it up the ramp
D what is the overall amount of work done on object moving up the ram
C it reduces the amount of useful work done on objects move it up the ramp
Name the type of motion executed by the motion of the moon around the earth.
Answer:
The motion of the moon around the earth is circular motion
Explanation:
Tres personas, A, B, C, jalan una caja con ayuda de cuerdas cuya masa es despreciable. Si la persona A aplica −3 en dirección horizontal y la persona B aplica a su vez 5 en dirección horizontal, ¿Cuál es el valor de la fuerza que debe ejercer la persona C, para que la caja esté en equilibrio físico?
Answer:
El valor de la fuerza que debe ejercer la persona C debe ser de -2 para que la caja esté en equilibrio físico.
Explanation:
Si la caja debe hallarse en equilibrio físico, entonces se debe satisfacer la siguiente ecuación:
[tex]F_{A} + F_{B} + F_{C} = 0[/tex] (1)
Si sabemos que [tex]F_{A} = -3[/tex] y [tex]F_{B} = 5[/tex], entonces el valor de la fuerza que debe ejercer la persona C debe ser:
[tex]F_{C} = -F_{A}-F_{B}[/tex]
[tex]F_{C} = -(-3)-5[/tex]
[tex]F_{C} = -2[/tex]
El valor de la fuerza que debe ejercer la persona C debe ser de -2 para que la caja esté en equilibrio físico.
A compound eye __________. ANSWER Unselected is composed of thousands of prisms that focus light onto only a few photoreceptor cells Unselected All of the listed responses are correct. Unselected works best for resolving stationary images Unselected contains many individual light detectors, each with its own lens Unselected is possessed only by insect
Answer:
contains many individual light detectors, each with its own lens
Explanation:
The compound eye is found mainly in insects and crustaceans, it is composed of individual receptor units, each with its focus, sensing nerve; each one gives a small image of the environment, so the image is mosaic type, not a complete integral image of the environment.
When reviewing the different statements, the correct one is
contains many individual light detectors, each with its own lens
what is velocity give its SI unit
Answer:
Velocity is the speed of something given in a direction. the SI unit of velocity is metre per second or m/s.
Please help!! :)
For this circuit, what will be the voltage drop across R1?
A. 21.3 V
B. 14.2 V
C. 45.0 V
D. 9.47 V
Answer:
Option D. 9.47 V
Explanation:
We'll begin by calculating the equivalent resistance of the circuit. This can be obtained as follow:
Resistor 1 (R₁) = 20 Ω
Resistor 2 (R₂) = 30 Ω
Resistor 3 (R₃) = 45 Ω
Equivalent Resistance (R) =?
R = R₁ + R₂ + R₃ (series connections)
R = 20 + 30 + 45
R = 95 Ω
Next, we shall determine the current in the circuit. This can be obtained as follow:
Voltage (V) = 45 V
Equivalent Resistance (R) = 95 Ω
Current (I) =?
V = IR
45 = I × 95
Divide both side by 95
I = 45 / 95
I = 0.4737 A
Finally, we shall determine, the voltage across R₁. This can be obtained as follow:
NOTE: Since the resistors are in series connection, the same current will pass through them.
Current (I) = 0.4737 A
Resistor 1 (R₁) = 20 Ω
Voltage 1 (V₁) =?
V₁ = IR₁
V₁ = 0.4737 × 20
V₁ = 9.47 V
Therefore, the voltage across R₁ is 9.47 V.
Answer:
9.47
Explanation:
Just Took the Test
a skydiver of mass 80kg jumpes from a plane. Taking g=m/s^2 write down the weight of skydiver
Answer:
800N
Explanation:
as we know that
weight = mass × acceleration due to gravity
= 80kg × 10 m/s^2
= 800N.
A car generator turns at 400 rpm (revolutions per minute) when the engine is idling. It has a rectangular coil with 300 turns of dimensions 5.00 cm by 6.46 cm that rotates in an adjustable magnetic field. What is the field strength needed to produce a 24.0 V peak emf
Answer:
The field strength needed to produce a 24.0 V peak emf is 0.5913 T
Explanation:
From the formula for maximum emf of a generator,
[tex]emf_{max}= NAB\omega[/tex]
∴ [tex]B = \frac{emf_{max} }{NA\omega}[/tex]
Where N is the number of loops
A is cross section of loops
B is magnetic field strength
ω is the angular frequency of loops
From the question, [tex]emf_{max} = 24.0V[/tex]
N = 300 turns
A = l × b ( since it is a rectangular coil)
A = 6.46 cm × 5.00 cm
A = 0.0646 m × 0.05 m
A = 0.00323 m²
ω = 400 rpm = (400/60)×2π rad/s
ω = 41.8879 rad/s
Putting all the parameters into the formula
[tex]B = \frac{emf_{max} }{NA\omega}[/tex]
[tex]B = \frac{24.0}{300\times0.00323\times41.8879}[/tex]
[tex]B = 0.5913T[/tex]
Hence, the field strength needed to produce a 24.0 V peak emf is 0.5913 T
