Answer:
W = 3.15 · 10⁶ J
Explanation:
We know that power is calculated using the formula:
P = W/twhere P = power (W), W = work (J), and t = time (s)We can derive a formula for work using this formula by multiplying t to both sides of the equation.
W = PtLet's convert 15 kW to W.
15 kW → 15,000 WLet's convert 3.5 min to s.
3.5 min → 210 sSubstitute these values into the formula for work and solve for W.
W = Pt W = (15,000 W) · (210 s) W = 3,150,000 J W = 3.15 · 10⁶ JThis is the amount of work done by a 15 kW engine in 3.5 minutes.
A uniform 140 g rod with length 57 cm rotates in a horizontal plane about a fixed, vertical, frictionless pin through its center. Two small 30 g beads are mounted on the rod such that they are able to slide without friction along its length. Initially the beads are held by catches at positions 11 cm on each sides of the center, at which time the system rotates at an angular speed of 23 rad/s. Suddenly, the catches are released and the small beads slide outward along the rod. Find the angular speed of the system at the instant the beads reach the ends of the rod. Answer in units of rad/s.
Answer:
The correct answer is "12 rad/s"
Explanation:
The given values are,
Mass of rod,
M = 140 g
i.e.,
= 0.14 kg
Length,
L = 57 cm
i.e.,
= 0.57 m
Mass of beads,
M = 30 g
i.e.,
= 0.03 kg
Angular speed,
r = 11 cm
i.e.,
= 0.11 m
Now,
The inertia of rods will be:
= [tex]\frac{1}{12}ML ^2[/tex]
On substituting the values, we get
= [tex]\frac{1}{12}\times 0.14\times (0.57)^2[/tex]
= [tex]0.0037905 \ kg-m^2[/tex]
The inertia of beads will be:
= [tex]mr^2[/tex]
On substituting the values, we get
= [tex]0.03\times (0.11)^2[/tex]
= [tex]0.000726 \ kg-m^2[/tex]
The total inertia will be:
= [tex]Inertia \ of \ rods+Inertia \ of \ beads[/tex]
= [tex]0.0037905 + 0.000726[/tex]
= [tex]0.0045165 \ kg-m^2[/tex]
now,
The angular speed of the system will be:
⇒ [tex]L_1w_1=L_2w_2[/tex]
On substituting the values in the above equation, we get
⇒ [tex]0.0045165\times 23 = (0.0037905 + (0.03\times 0.285^2)\times 2 )\times w_2[/tex]
⇒ [tex]0.1038795 = 0.0037905 + (0.00243675\times 2 )\times w_2[/tex]
⇒ [tex]w_2 = 12 \ rad/s[/tex]
A wave of frequency 500hz and wave length 50m is traveling into a medium, dertimine the speed of velocity of the wave. formula V=f×d.
Answer:
25000m/s
Explanation:
V=fd
V=(500)(50)
V=25000m/s
Ans
Sep 19, 2019 — Wave speed is the distance a wave travels in a given amount of time, such as the ... Wave speed is related to both wavelength and wave frequency. ... The equation for wave speed can be used to calculate the speed of a wave when both ... Frequency = SpeedWavelength or Wavelength = SpeedFrequency.
Explanation:
Will the 79 kg skier in the figure below slide down if f the coefficient of static friction is 0.25?
Answer:
Man will not slide down
Explanation:
Given:
Coefficient of static friction = 0.25
Angle = 13°
Computation:
Man will slide down if
tan13° > Coefficient of static friction
Tan 13 = 0.23
So,
0.23 < 0.25
So,
Man will not slide down
When you measure the mass of an object you are also measuring its what
Here ya go-!
Mass is both a property of a physical body and a measure of its resistance to acceleration (a change in its state of motion) when a net force is applied. An object's mass also determines the strength of its gravitational attraction to other bodies. The basic SI unit of mass is the kilogram (kg).
(um im sorry if its wrong-)
A cart moves with negligible friction or air resistance along a roller coaster track. The cart starts from rest at the top of a hill of unknown height. It then goes down that first hill and up another circularly shaped hill of height 10 meters and radius 15 meters. The ride is designed so that the cart just barely loses contact with the track at the top of the second hill (10 meters above ground level). What is the height of the starting hill relative to ground
Answer:
hinit = 17.5 m
Explanation:
Assuming no friction present, the mechanical energy must be conserved, which means that at any point of the trajectory, the sum of the gravitational potential energy and the kinetic energy must keep the same.At the top of the hill, since it starts from rest, all the energy must be potential, and we can express it as follows:[tex]E_{o} = U_{o} = m*g*h_{init} (1)[/tex]
When the car arrives to the top of the second hill, as we know that it is lower than the first one, the energy of the car, must be part gravitational potential energy, and part kinetic energy.We can express this final energy as follows:[tex]E_{f} = U_{f} + K_{f} = m*g* h_{2} + \frac{1}{2} *m*v_{f} ^{2} (2)[/tex]
In order to find hinit, we need to make (1) equal to (2), and solve for it.In (2) we have the value of h₂ (10 m), but we still need the value of the speed at the top of the second hill, vf.Now, when the car is at the top of the hill, there are two forces acting on it, in opposite directions: the normal force (upward) and the weight (downward).We know also that there is a force that keeps the car along the circular track, which is the centripetal force.This force is just the net downward force acting on the car (it's vertical at the top), and is just the difference between the weight and the normal force.If the cart just barely loses contact with the track at the top of the second hill, this means that at that point the normal force becomes zero.So, the centripetal force must be equal to the weight.The centripetal force can be expressed as follows:[tex]F_{c} = m*\frac{v_{f} ^{2}}{R} (3)[/tex]
We have just said that (3) must be equal to the weight:[tex]F_{c} = m*\frac{v_{f} ^{2}}{R} = m*g (4)[/tex]
Simplifying, and rearranging, we can solve for vf², as follows:[tex]v_{f}^{2} = R*g (5)[/tex]
Replacing (5) in (2), simplifying and rearranging in (1) and (2) we finally have:[tex]h_{init} = h_{2} + \frac{1}{2} R = 10m + 7.5 m = 17.5 m (6)[/tex]
1. Why is the flow of electrons from A to B?
2. What's the difference between flow of current & flow of electrons and why ar they opposite?
1. because A is more negative than B. A is -1000 V (we can imagine that A has excess 1000 electrons), in other, B which +3000 V can be assume that B need 3000 elctrons to be neutral. So, the electron will flow from A to B.
2. Electrons being negatively charged flow from the negative terminal to the positive terminal of the voltage source. So, the actual direction of current should be from negative to positive terminal. However, the conventional direction had already been established. So, the current flow is considered in the direction opposite to the direction of flow of electrons. (from topperlearning dot com)
who compose the Ghana national anthem
Answer:
Philip Gbeho
Explanation:
a box is slides down a slope
Answer:
120 N
Explanation:
From the question given above, the following data were obtained:
Angle (θ) = 35°
Mass (m) = 15 Kg
Acceleration due to gravity (g) = 9.8 m/s²
Normal force (N) =?
The normal force acting on the object can be obtained as:
N = mg × Cosθ
N = 15 × 9.8 × Cos 35
N= 147 × 0.8192
N = 120 N
Therefore, the normal force acting on the object is 120 N
faraday's law states that the potential difference can be increased by... (choose all that apply)
1. using static electricity instead of current electricity
2. increase the number of coils, increase the strength of the magnet
3. using a bunch of small magnets
4. increasing the time used to power up an electromagnet
5. increase the speed of the magnet
Id say its the last option of the fourth option
Explanation:
Answer:
1:increase the number of coils, increase the strength of the magnet
2:increase the speed of the magnet
3: increasing the time used to power up an electromagnet
Explanation:
1). Increasing the number of turns of wire in the coil – By increasing the amount of individual conductors cutting through the magnetic field, the amount of induced emf produced will be the sum of all the individual loops of the coil, so if there are 20 turns in the coil there will be 20 times more induced emf than in one piece of wire.
2). Increasing the speed of the relative motion between the coil and the magnet – If the same coil of wire passed through the same magnetic field but its speed or velocity is increased, the wire will cut the lines of flux at a faster rate so more induced emf would be produced.
3). Increasing the strength of the magnetic field – If the same coil of wire is moved at the same speed through a stronger magnetic field, there will be more emf produced because there are more lines of force to cut.
Air plane travels 224 in 2 hours.
How fast was the plane traveling?
Answer:
112mph
Explanation:bugyg
(WILL MARK BRAINLIAST)( 1 answer question.. look the photo)
As the cars come closer together, the amount of potential energy in the system:
-Increases
-Decreases
-Stays the same
Answer:
increases
Explanation:
due to less speed
what is the reason for timing more than one oscillation in a simple pendulum
Answer:
Time period is the time taken by the body to complete one oscillation and it is noted more than once to get accurate reading from averaging of all the observed values.
Three cylindrical wires, 1, 2, and 3 are made of the same materialand have resistances R1, R2, and R3, respectively. Wires 1 and 2 have the same lengthbut diameter of wire 2 is twice that of wire 1. Wires 2 and 3 have the same diameterbut length of wire 3is twice that of wire 2.
1. Rank the wires according to their resistances, greatest first.
A. R1> R2> R3R1
B. R1> R3> R2R2
C. R2> R1> R3R3
D. R2> R3> R1
E. R3> R1> R2
F. R3> R2> R1Q2.
2. If same voltage is applied across each of the wires, which one will dissipate heat at the highest rate
Answer:
1) R₁ > R₃ > R₂ correct B , 2) the wire that dissipates the most is wire 2
Explanation:
1) The resistance of a wire is given by the expression
R = [tex]\rho \ \frac{l}{A}[/tex]
where ρ is the resistivity of the material, l the length of the wire and A the area of the wire
The area is given by
A = π r² = π d² / 4
we substitute
R = (ρ 4 /π) [tex]\frac{l}{d^2}[/tex]
the amount in parentheses is constant for this case
let's analyze the situation presented, to find the resistance of each wire
* indicate l₁ = l₂ and d₂ = 2 d₁
the resistance of wire 1 is
R₁ = (ρ 4 /π) [tex]\frac{l_1}{d_1^2}[/tex]
the resistance of wire 2 is
R₂ = (ρ 4 /π) \frac{l_2}{d_2^2}
R₂ = (ρ 4 /π) [tex]\frac{l_1}{ (2 d_1)^2}[/tex]
R₂ = (ρ 4 /π ) [tex]\frac{l_1}{d_1^2}[/tex] ¼
R₂ = ¼ R₁
* indicate that d₂ = d₃ and l₃ = 2 l₂
R2 = (ρ 4 /π) [tex]\frac{l_2}{d_2^2}[/tex]
the resistance of wire 3 is substituting the indicated condition
R3 = (ρ 4 /π 2) \frac{l_3}{d_3^2}
R3 = (ρ 4 /π) [tex]\frac{2 \ l_2}{d_2}[/tex]
R3 = 2 R₂
let's write the relations obtained
R₁ = (ρ 4 /π) [tex]\frac{I_1}{ d_1^2}[/tex]
R₂ = ¼ R₁
R₃ = 2 R₂
let's write everything as a function of R1
R₁ =(ρ 4 /π) [tex]\frac{l_1}{d_1^2}[/tex]
R₂ = ¼ R₁
R₃ = ½ R₁
the resistance of the wire in decreasing order is
R₁ > R₃ > R₂
2) The power dissipated by a wire is
P = V I
the voltage is
V = I R
I = V / R
substituting
P = V² / R
therefore the power dissipated by each wire is
wire 1
P₁ = V² / R₁
wire 2
P₂ = V² / R₂
P₂ = [tex]\frac{V^2}{ \frac{1}{4} R_1}[/tex]
P₂ = 4 P₁
wire 3
P₃ = V² / R₃
P₃ = [tex]\frac{V^2}{ \frac{1}{2} R_1}[/tex]
P₃ = 2 P₁
Therefore, the wire that dissipates the most is wire 2
The microwaves produced inside a microwave have a wavelength of 12.0m and a frequency of 25Hz. At what speed do the microwaves travel in units of m/s ?
Answer: 300 m/s
Explanation:
The equation for finding wave speed is the wavelength times the frequency which would be
12.0mx 25hz=300m/s
Which of the following is a conductor?
copper
water
aluminum
all of the above
Answer:
D all of the above
Explanation:
electricity moves easily through all of them and none of them prevent the flow of electricity
The amount of sliding friction depends on the
a. weight of the moving object and the type of surface that the
object slides across.
b. density and volume of the object.
c. acceleration and mass of the object.
d. density and mass of the object.
*help please
Answer:
c I think so do u know the formula for friction??friction? lkke kinetic friction
An elevator motor in a high-rise building can do 3500 kJ of work in 5 min. Find the power developed by the motor. Explain if you can plz
Answer:
P = 11666.6 W
Explanation:
Given that,
Work done by the motor, W = 3500 kJ
Time, t = 5 min = 300 s
We need to find the power developed by the motor. Power developed is given by :
[tex]P=\dfrac{E}{t}\\\\P=\dfrac{3500\times 10^3}{300}\\\\P=11666.7\ W[/tex]
So, the required power is 11666.6 W.
Within which type of system is the total energy conserved?
A. Isolated
B. Connected
C. Closed
D. Open
The total energy is conserved within isolated system.
How is energy conserved in an isolated system?In an isolated system, there is no exchange of matter or energy with the surroundings. Therefore, the total energy within the system remains constant, meaning that energy is conserved within the system.
In contrast, in an open system, there can be an exchange of both matter and energy with the surroundings, so the total energy within the system is not necessarily conserved.
In a closed system, there can be an exchange of energy but not matter, so the total energy within the system is conserved as long as there is no work being done by or on the system. In a connected system, the term is not commonly used in the context of energy conservation.
Learn about isolated system here https://brainly.com/question/17580023
#SPJ1
A human body consists of
Answer:
60% of the human adult body is water. According to H.H. Mitchell, Journal of Biological Chemistry 158, the brain and heart are composed of 73% water, and the lungs are about 83% water. The skin contains 64% water, muscles and kidneys are 79%, and even the bones are watery: 31%.
Explanation:
PLEASE HELP ME WITH ONE QUESTION
If 1000 J of heat energy is lost from a piece of hot metal which is placed into a cup of cool water, how much energy is gained by the water?
Answer:
1000J
Explanation:
According to the law of calorimetry;
Heat lost by cold substance = Heat gained by hot substance
If 1000 J of heat energy is lost from a piece of hot metal,
heat lost by hot substance = 1000J
Since we are to determine how much energy is gained by the water, using the law
Heat lost by hot metal = heat gained by the water
Hence heat gained by the water = 1000J
Please help
The period of an oscillation is measured to be 0.0833 seconds. What is
the frequency of this oscillation? *
1.0833 Hz
0.287 Hz
9.8 Hz
12 Hz
0.007 Hz
Answer:
your
answer is
12.004
The statement "If a plant receives fertilizer,
then it will grow to be bigger than a plant
that does not receive fertilizer" is an
example of
A. an observation.
B. a hypothesis.
C. a theory.
Expository essay "Climate change in Fiji"
Answer: Climate change poses to the tourism development in Fiji islands. It shows the adverse effects of the changing climate and the dangers pose by the tourism activities and also pose a major hazard for the local people in the region. It also deals with the dangerous carbon emissions and CO2 effect on the landscape, food, water, energy.
The pacific is the world`s largest ocean with a surface area of 175 million sq km and constitutes for 40% of the planet`s waters. Located in the tropical latitudes, it covers more than half the globe`s circumference. Temperature of the surface water in the western tropical regions is always more than 28 ÌŠC over a depth of several hundred meters. This makes up the world`s storage of thermal energy for exchange with atmosphere. Here the interaction between atmosphere and ocean is most extreme and influences the climate not only regionally but planet-wide. The nations of the pacific are obscured human settlements absorbed in this vast fluid universe. The ocean is the most important factor controlling the environment and life.
A student sets up a standing wave of wavelength 6 meters in a coiled spring by moving his hand up and down twice each second. What is the velocity of the wave?
Answer:
Velocity = 12 m/s
Explanation:
Given the following data;
Wavelength = 6 meters
Period = 0.5 seconds. This is due to the fact that the student is moving his hand up and down twice each second.
To find the velocity;
Velocity = wavelength * frequency
But, frequency = 1/period
Frequency = 1/0.5
Frequency = 2
Substituting the values into the velocity formula, we have;
Velocity = 6 * 2
Velocity = 12 m/s
Therefore, the velocity of the wave is 12 meters per seconds.
PLEASE HELP ME WITH THIS ONE QUESTION
A tuning fork of 500 Hz is struck in a room with a speed of sound of 340 m/s. What is the distance between a point of rarefaction and the next compression point, in the resulting sound?
Answer:
0.34 m
Explanation:
From the question,
v = λf................ Equation 1
Where v = speed of sound, f = frequency, λ = Wave length
Make λ the subject of the equation
λ = v/f............... Equation 2
Given: v = 340 m/s, f = 500 Hz.
Substitute these values into equation 2
λ = 340/500
λ = 0.68 m
But, the distance between a point of rarefaction and the next compression point, in the resulting sound is half wave length
Therefore,
λ/2 = 0.68/2
λ/2 = 0.34 m
Hence, the distance between a point of rarefaction and the next compression point, in the resulting sound is 0.34 m
We can model a pine tree in the forest as having a compact canopy at the top of a relatively bare trunk. Wind blowing on the top of the tree exerts a horizontal force, and thus a torque that can topple the tree if there is no opposing torque. Suppose a tree's canopy presents an area of 9.0 m2 to the wind centered at a height of 7.0 m above the ground. (These are reasonable values for forest trees.)
Answer:
A,)FD= 114.1N
B)Torque=798.5Nm
Explanation:
We can model a pine tree in the forest as having a compact canopy at the top of a relatively bare trunk. Wind blowing on the top of the tree exerts a horizontal force, and thus a torque that can topple the tree if there is no opposing torque. Suppose a tree's canopy presents an area of 9.0 m^2 to the wind centered at a height of 7.0 m above the ground. (These are reasonable values for forest trees.)
If the wind blows at 6.5 m/s, what is the magnitude of the drag force of the wind on the canopy? Assume a drag coefficient of 0.50 and the density of air of 1.2 kg/m^3
B)What torque does this force exert on the tree, measured about the point where the trunk meets the ground?
A)The equation of Drag force equation can be expressed below,
FD =[ CD × A × ρ × (v^2/ 2)]
Where CD= Drag coefficient for cone-shape = 0.5
ρ = Density
Area of of the tree canopy = 9.0 m^2
density of air of = 1.2 kg/m^3
V= wind velocity= 6.5 m/s,
If we substitute those values to the equation, we have;
FD =[ CD × A × ρ × (v^2/ 2)]
F= [ 0.5 × 9.0 m^2 × 1.2 kg/m^3 ( 6.5 m/s/ 2)]
FD= 114.1N
B) the torque can be calculated using below formula below
Torque= (Force × distance)
= 114.1 × 7
= 798.5Nm
1. Only about
% of water on Earth is fresh water that is readily available for human consumption.
a. less than 1
b. 5
c. more than 50
d. All water on Earth is fresh water and is easily accessible.
Answer:
Hey mate.....
Explanation:
This is ur answer....
a. Less than 1%3% of the earth's water is fresh. 2.5% of the earth's fresh water is unavailable: locked up in glaciers, polar ice caps, atmosphere, and soil; highly polluted; or lies too far under the earth's surface to be extracted at an affordable cost. 0.5% of the earth's water is available fresh water....
Hope it helps you,
Mark me brainliest plz....
Follow me! :D
Question:
1. Only about % of water on Earth is fresh water that is readily available for human consumption.
a. less than 1
b. 5
c. more than 50
d. All water on Earth is fresh water and is easily accessible
Answer:
a. less than 1
how much force is needed to accelerate a 2500kg car at a rate of 4m/s2
Answer:
10,000 N
Explanation:
Using Newton's Second Law of Motion, Force = Mass*Acceleration.
Plugin 2500 kg for the mass and 4 m/s^2 for the acceleration.
Force = 2500 kg*4 m/s^2 = 10000 Newtons
(SI unit of force is Newtons)
Find the velocity of a dolphin that swims 55 m in 5.0 s.
Answer: 11 m/s
Explanation: velocity = distance /time = 55 m /5.0 s
Answer:40km/h
Explanation:
You want to use a metal bar as a resistor. Its dimensions are 1 by 3 by 13 units. To get the largest resistance from the bar, you should attach leads to the two opposite sides that have dimensions of 1 by 3 units. All configurations give the same resistance. 3 by 13 units. 1 by 13 units. None of the above.
Answer:
1 by 3 units
Explanation:
The resistance (R) of a conductor is given by the formula:
R = ρL / A
where L is the length of the conductor, ρ is resistivity and A is the cross sectional area.
Let us assume that the metal bar has a resistivity of ρ.
a) If the leads is attached to the two opposite sides that have dimensions of 1 by 3 units.
The length of the bar would be 13 units and the cross sectional area (A) would be = 1 * 3 = 3 units²
R₁ = ρL / A = ρ(13) / 3 = 13ρ / 3
b) If the leads is attached to the two opposite sides that have dimensions of 3 by 13 units.
The length of the bar would be 1 units and the cross sectional area (A) would be = 3 * 13 = 39 units²
R₂ = ρL / A = ρ(1) / 39 = ρ / 39
c) If the leads is attached to the two opposite sides that have dimensions of 1 by 13 units.
The length of the bar would be 3 units and the cross sectional area (A) would be = 1 * 13 = 13 units²
R₃ = ρL / A = ρ(3) / 13 = 3ρ / 13
Therefore we can see that the largest resistance is gotten If the leads is attached to the two opposite sides that have dimensions of 1 by 3 units