Answer:
12 i. The work done by Wale = 107.910 kJ
The work done by Lekan = 117.720 kJ
Total work done = 225.36 kJ
ii. Wale's power = 4.3164 kW
Lekan's power = 3.924 kW
Wale has more power and is more powerful than Lekan
13. 313.92 N
Explanation:
i. The work done, W = Force, F × Distance moved by the force, D
The given parameters are
The mass of Wale = 55 kg
The mass of Lekan = 60 kg
The acceleration due to gravity, g =9.81 m/s²
The motion force of Wale and Lekan are;
Motion force of Wale = 9.81 × 55 = 539.55 N
Motion force of Lekan = 9.81 × 60 = 588.6 N
The work done by Wale = 539.55 × 200 = 107910 J = 107.910 kJ
The work done by Lekan= 588.6 × 200 = 117720 J = 117.720 kJ
107910 + 117720 =225630 J = 225.36 kJ
ii. Power = Work done/time
Wale finished the race in 25 s, therefore, his power = 107910/25 = 4316.4 W
Lekan finished the race in 30 s, therefore, his power = 117720/30 = 3924 W
Wale has more power and is more powerful than Lekan
13. The velocity ratio = 5
V. R. = Distance moved by effort/(Distance moved by load)
Efficiency = 80%
Work done by effort = x
Work done by machine = Efficiency × Work done by effort = 0.8 × x
Distance moved by effort, E = V. R. × Distance moved by load, D = 5 × D
Work done by effort = Force × Distance moved = 200×9.81× E
Work done by effort = 1962×E = 1962×E = 1962×5×D
Work done by machine = 1962 × D, when D = 1, we have;
0.8 × 1962×1 = 1569.6 J
Work done by effort = Force × Distance moved
Work done by effort = Force × 5×D = Force × 5 (D = 1)
From the principle of conservation of energy, we have;
Energy is neither created nor destroyed
Therefore
Work done by effort = Force × 5 = 1569.6 J
Force = 1569.6 /5 = 313.92 N.
-
Speed is a scalar, a quantity that is
described by
alone.
Answer:
True
Explanation:
Thats is true since it cannot be a vector because speed only gives a magnitude, not a direction as well.
If an object has a mass of 200kg but its Ke is 40J, what is its speed?
Answer:
0.632456 m/s
Explanation:
The distance covered by a body along the x axis is given by x=2t^3+5t^2+t where t is measured in seconds and x is in meter. Find average speed in a time interval from t= 0s and t=2s
Explanation:
It is given that,
The distance covered by a body along the x-axis is given by :
[tex]x=2t^3+5t^2+t[/tex]
t is in seconds and x is meters
Speed of the body is given by :
[tex]v=\dfrac{dx}{dt}\\\\v=\dfrac{d(2t^3+5t^2+t)}{dt}\\\\v=6t^2+10t+1[/tex]
At t = 0,
[tex]v=6(0)^2+10(0)+1=1\ m/s[/tex]
At t = 2 s,
[tex]v=6(2)^2+10(2)+1=45\ m/s[/tex]
So, the average speed in a time interval from t= 0s and t=2s is 45 m/s.
A baseball pitcher throws a 0.14 kg ball toward a batter who is 18 m away.
The ball is traveling at 40 m/s when it leaves the pitcher's hand. What is the
ball's kinetic energy at this point?
A. 112 J
OB. 224 J
C. 12J
D. 3 J
SUBMIT
Answer:
A. 112 J
Explanation:
KE = ½mv² = ½(0.14)40² = 112 J
An American traveler in Kenya carries a transformer to convert Kenya's standard 240 V to 120 V so that she can use some small appliances on her trip. (a) What is the ratio of turns in the primary and secondary coils of her transformer? Np Ns = (b) What is the ratio of input to output current? Iin Iout = (c) How could a Kenyan traveling in the United States use this same transformer to power her 240 V appliances from 120 V?
Answer:
a) [tex]N_{p}[/tex]/[tex]N_{s}[/tex] = 2
b) [tex]I_{in}[/tex]/[tex]I_{out}[/tex] = 0.5
c) A Kenyan travelling in the united states will now use the output terminal of the transformer in Kenya as the input terminal in the United States, to step up the voltage from 120 V to 240 V for his devices
Explanation:
Kenya's standard voltage [tex]V_{p}[/tex] = 240 V
America's standard voltage [tex]V_{s}[/tex] = 120
using the transformer relationship
[tex]V_{p}[/tex]/[tex]V_{s}[/tex] = [tex]N_{p}[/tex]/[tex]N_{s}[/tex]
substituting values, we have
240/120 = [tex]N_{p}[/tex]/[tex]N_{s}[/tex]
[tex]N_{p}[/tex]/[tex]N_{s}[/tex] = 2
b) The power input must be equal to the power output
[tex]I_{in}[/tex][tex]V_{in}[/tex] = [tex]I_{out}[/tex][tex]V_{out}[/tex]
where [tex]I_{in}[/tex] = input current
[tex]V_{in}[/tex] = input voltage = 240 V
[tex]I_{out}[/tex] = output current
[tex]V_{out}[/tex] = output voltage = 120 V
Transposing the above equation, we get
[tex]I_{in}[/tex]/[tex]I_{out}[/tex] = [tex]V_{out}[/tex]/[tex]V_{in}[/tex]
[tex]I_{in}[/tex]/[tex]I_{out}[/tex] = 120/240 = 0.5
c) A Kenyan travelling in the united states will now use the output terminal of the transformer in Kenya as the input terminal in the United States, to step up the voltage from 120 V to 240 V for his devices.
How do we find the weight of a beam
Answer:
Standard weight: We calculate the standard weight as follows: G = L * mweight, where L is the length of the beam calculated as the difference between the extreme points of the beam body along the direction of the beam axis, taking into account all features except holes.
Explanation:
I want Brainliest plz!!
: Lili
To see if your results are reasonable, you can compare the final velocity of the stone as it falls down unwinding the wire from the pulley, to the velocity the stone would have if falling the same distance while unconnected to the pulley. What is the velocity of an untethered stone after falling 0.337 m from rest
Answer:
The velocity of the stone is 2.57 m/s.
Explanation:
Given that
Height = 0.337 m
We need to calculate the velocity of the stone
Using equation of motion
[tex]v^2-u^2=2gh[/tex]
Where, v = velocity of stone
u = initial velocity
g = acceleration due to gravity
h = height
Put the value into the formula
[tex]v^2-0=2\times9.8\times 0.337[/tex]
[tex]v=\sqrt{2\times9.8\times0.337}[/tex]
[tex]v=2.57\ m/s[/tex]
Hence, The velocity of the stone is 2.57 m/s.
Joseph jogs from one end A to the other end B of a straight 300 m road in 2 minutes 30 seconds and then turns around and jogs 100 m back to point C in another 1 minute. What are Joseph's average speeds and velocities in jogging (a) from A to B and (b) from A to C?
Answer:
Explanation:
(a) It is given that Joseph jogs on a straight road of 300m in a time interval of 2 minutes and 30 seconds, which is equal to 150seconds. Therefore, when Joseph jogs from point A to point B, he covers a distance of 300m in time of 150seconds. Hence, his average speed is 300m/150s=2ms^−1. Since it is a straight road and he jogs in a single direction in this case, his displacement is equal to 300m. Since it is a straight road and he jogs in a single direction in this case, his displacement is equal to 300m.
Hence, his average velocity is 300m/150s=2ms^−1
(b) Then it is given that he turns back and points B and jogs on the same road but in the opposite direction for a time interval for 1 minute and covers a distance of 100m.If we consider the whole motion of Joseph, i.e. from point A to point C, then he covers a total distance of 300m+100m=400m. And he covers this total distance in a time interval of 2.5min+1min=3.5min=210s.
Therefore, his average speed for this journey is 400m210s=1.9ms−1.
For the same journey is displacement is equal to the distance between the points A and C,i.e. 300m−100m=200m.
Hence, his average velocity for this case is 200m/210s=0.95ms^−1
A ball with a mass of 0.5 kg is attached to one end of a light rod that is 0.5 m long. The other end of the rod is loosely pinned at a frictionless pivot. The rod is raised until it is vertical, with the ball above the pivot. The rod is released and the ball moves in a vertical circle. The tension in the rod as the ball moves through the bottom of the circle is closest to:
Answer:
The tension in the rod as the ball moves through the bottom circle is 9.8 N
Explanation:
When the ball is released from rest, the centripetal force equals the weight of the ball. So mv²/r = mg where m = mass of ball = 0.5 kg, v = speed of ball, r = radius of vertical circle = length of rod = 0.5 m and g = acceleration due to gravity = 9.8 m/s²
v = √gr = √9.8 m/s² × 0.5 m = √4.9 = 2.21 m/s
Now at the bottom of the circle T - mg = mv²/r where T = tension in the rod
T = m(g + v²/r)
= m(g + (√gr)²/r)
= m(g+ gr/r)
= m(g + g)
= 2mg
= 2 × 0.5 kg × 9.8 m/s²
= 9.8 N
So, the tension in the rod as the ball moves through the bottom circle is 9.8 N
What is principle of liver??
Answer:
lever: Principle of the Lever
lever: Principle of the LeverIt has been found by experiment that two equal forces acting in opposite directions, i.e., clockwise and counterclockwise, and applied to a uniform lever at equal distances from the fulcrum counteract each other and establish a state of equilibrium, or balance, in the lever.
observe the virual skateboarder coming down the hill and over the ramp describe how each of newton’s laws of motion can be observed in this action you can choose the dry wet or muddy conditions or some combination of these
Answer:
first part the skater goes down a constant slope ramp, initially he has Newton's second law
pply Newton's third law, the normal is the reaction to the support of the body on the surface
the ramp shoots off. axis becomes zero and therefore with Newton's first law its speed
Explanation:
It is the description of this movement let's write Newton's laws.
* The first law that a body goes at constant speed or zero if the sum of the external forces is zero
* the second law is F = m a
* The third law states that the forces act in pairs of equal magnitude and opposite direction, one applied to each body.
Let's apply these laws to our case
In the first part the skater goes down a constant slope ramp, initially he has Newton's second law when he accelerates from the initial velocity of zero to a terminal velocity.
The expression for this is
Wₓ - fr = ma
W sin θ - μ W cos θ = m a
W = mg
g (sin θ - μ cos) = a
the value of the coefficient of kinetic friction depends on the condition of the surface, dry, wet or muddy
This is Newton's second law
On the Y axis, which is perpendicular to the ramp we have
N- [tex]W_{y}[/tex] = 0
If we apply Newton's third law, the normal is the reaction to the support of the body on the surface, note that it can be different from the weight.
In the second part when he is on the ramp.
In the ramp the skater enters with a speed v, suppose that the ramp has an incline so that the skater can jump, in this case the angle is positive with respect to the axis x
In this case the analysis is similar to the previous one
Newton's second law gives the acceleration of the skater, who when he reaches the end of the ramp shoots off.
At this point the force in the x (horizontal) axis becomes zero and therefore with Newton's first law its speed this axis remains constant and the force in the y axis is the force of gravity and has an acceleration that changes if velocity according to Newton's second law
Answer:look at explanations
Explanation:
What is the voltage of the power source if a motor with a resistance of 20 2 draws a
current of 1.5 A?
Answer:
190v I believe
hope this helped a little and if it did pls mark brainiest :)
Answer answer answer it it it
Answer:
(B) Parachutes
Explanation:
Air resistance works to slow down trains and airplanes, so it isn't desirable. Air resistance also causes pendulums to slow and stop.
Parachutes need air resistance to slow a person's fall. So air resistance is desirable here.
Answer:
B i answered it it it
Explanation:
what is system? Define
Answer:
a system is a set of some things which helps the good happenings in ousr day to day life. It also helps the astrophysisists to find the planets with a system
A 5kg block is pushed 3m at a constant velocity up a vertical wall by a constant force applied at an angle of 37 degree with the horizontal, if the coefficient of kinetic friction between the block and the wall is 0.3. what is the work done by the force on the block?
The work done by the force on the block is:
[tex]W=135.41*3=406.23 \: J[/tex]
The direction of motion here is in the y-direction, so we need to find the component of the force in this direction.
Using trigonometric functions:
[tex]F_{y}=Fsin(37)[/tex]
This component is in the positive y-direction.
Now, there is a friction force between the block and the wall, so we need to find the friction force.
[tex]F_{f}=\mu N[/tex]
Where:
μ is the coefficient of kinetic frictionN is the normal force (Here N = Fcos(37))Let's use the first Newton's Law to get F.
F(y) is upward (+) and F(f) and the weight is downward (-).
[tex]F_{y}-F_{f}-W=0[/tex]
[tex]F_{y}-F_{f}=mg[/tex]
Factoring F in the left side:
[tex]F(sin(37)-\mu cos(37))=mg[/tex]
[tex]F=\frac{mg}{sin(37)-\mu cos(37)}[/tex]
[tex]F=\frac{5*9.81g}{sin(37)-(0.3*cos(37))}[/tex]
[tex]F=135.41\: N[/tex]
Therefore, the work done will be:
[tex]W=Fd[/tex]
[tex]W=135.41*3=406.23 \: J[/tex]
You can learn more about work definition here:
https://brainly.com/question/17231715
"For a first order instrument with a sensitivity of .4 mV/K and a time" constant of 25 ms, find the instrument’s response as a function of time for a sudden temperature increase from 273 K to 473 K. Before the temperature increase, the instrument output was a steady 109.2 mV. Plot the response y(t) as a function of time. What are the units for y(t)? Find the 90% rise time for y(t90) and the error fraction, Γ(t90).
Answer:
Explanation:
Given that:
For a first order instrument with a sensitivity of .4 mV/K
constant c = 25 ms = 25 × 10⁻³ s
The initial temperature [tex]T_1[/tex] = 273 K
The final temperature [tex]T_2[/tex] = 473 K
The initial volume = 0.4 mV/K × 273 K = 109.2 V
The final volume = 0.4 mV/K × 473 K = 189.2 V
the instrument’s response as a function of time for a sudden temperature increase can be computed as follows:
Let consider y to be the function of time i.e y(t).
So;
y(t) = 109.2 + (189.2 - 109.2)( 1 - [tex]\mathbf{e^{-t/c}}[/tex])mV
y(t) = (109.2 + 80 ( 1 - [tex]\mathbf{e^{t/25\times 10^{-3}}}[/tex])) mV
Plot the response y(t) as a function of time.
The plot of y(t) as a function of time can be seen in the diagram attached below.
What are the units for y(t)?
The unit for y(t) is mV.
Find the 90% rise time for y(t90) and the error fraction,
The 90% rise time for y(t90) is as follows:
Initially 90% of 189.2 mV = 0.9 × 189.2 mV
= 170.28 mV
170.28 mV = (109.2 + 80 ( 1 - [tex]\mathbf{e^{t/25\times 10^{-3}}}[/tex])) mV
170.28 mV - 109.2 mV = 80 ( 1 - [tex]\mathbf{e^{t/25\times 10^{-3}}}[/tex])) mV
61.08 mV = 80 ( 1 - [tex]\mathbf{e^{t/25\times 10^{-3}}}[/tex])) mV
0.7635 mV = ( 1 - [tex]\mathbf{e^{t/25\times 10^{-3}}}[/tex])) mV
t = 1.44 × 25 × 10⁻³ s
t = 0.036 s
t = 36 ms
The error fraction = [tex]\dfrac{189.2-170.28 }{189.2}[/tex]
The error fraction = 0.1
The error fraction = 10%
An average skater averages 11 m/s over the first 5 seconds of a race. find the average speed required over next 10 seconds to average 12 m/s overall.
Answer:
usa
Explanation:
Define potentiol energy , kenetic energy.
Potential energy is stored energy. For example, if a bowling ball is on top of a giant hill, we say it has potential energy because it has the potential to do work which is to roll down the hill.
Kinetic energy is the energy of movement so once that ball rolls down that hill, that potential energy is converted to kinetic energy.
Hey there!
Potential energy and kinetic energy are the two main groups of energy when it comes to all of that. Potential energy is stored energy. Kinetic energy is the energy that is released.
For example, potential energy is when you hold a ball higher than the ground, and kinetic energy is when you release the ball.
Hope this helps! Have a great day! :)
Can ya pls answer dis rq!
Answer:
For vegetarians beans
Explanation:
Because it's plant protein and very proteinious
A concave mirror has a radius of curvature of 80cm. If the real image of an object is formed at 1m, how far from the mirror is the object?
Answer:
66.7 cm
Explanation:
The focal length is half the radius of curvature, or f = 40 cm.
The image is real, so i = +100 cm.
The distance to the object is therefore:
1/o + 1/f = 1/i
1/o + 1/40 = 1/100
o = -66.7 cm
The object is 66.7 cm left of the mirror.
If 5 complete oscillations of a sound wave pass through a point in 0.5 s and the speed of sound was recorded to be 10 m/s, then find the wavelength of the sound.
Answer:
λ = 2.5m
Explanation:
Given the following :
Speed of sound (v) = 10m/s
If 5 oscillations pass through a point in 0.5seconds;
Time taken (period) for 1 oscillation is :
Number of oscillations / total time taken
5 / 0.5 = 0.25 seconds
Wavelength, period and Velocity are related by the formula:
v = λ / T
λ = v * T
λ = 10 * 0.25
λ = 2.5 m
A car travels from point A to B in 3 hours and returns back to point A in 5 hours. Points A and B are 150 miles apart along a straight highway. Which of the following statements most accurately describes the motion of the car? Choose 1 answer:(Choice A) A The average velocity is 40 miles per hour. (Choice B) B The total displacement of the trip is 300 miles. (Choice C) C The average speed is 37.5 miles per hour. (Choice D) D The car travels at 50 mph for the first half and 30 mph for the second half.
Answer: D
Explanation:
Given that a car travels from point A to B in 3 hours and returns back to point A in 5 hours. Points A and B are 150 miles apart along a straight highway.
From point A to B
The speed = distance / time
Where
Distance = 150 mile
Time = 3 hours
Substitute the values into the formula
Speed = 150/3 = 50 mile/ hours
From Point B to Point A
Distance = 150 miles
Time = 5 hours
Where speed = distance/ time
substitute all the parameters into the formula
Speed = 150/5 = 30 mph
Therefore, The car travels at 50 mph for the first half and 30 mph for the second half.
The correct answer is option D
Wagonium-292 has a half-life of 1 hour. If you started with an 80 gram sample, how much Wagonium-292 will remain after 4 hours? A.) 10g B.) 40g C.) 160g D.) 5G
After 1 hour, 80 g decays to 40 g.
After another hour (total 2 hours), 40 g decays to 20 g.
After another hour (total 3), 20 g decays to 10 g.
After one more hour (total 4), 10 g decays to (D) 5 g.
A magnet pulls a piece of iron with a force of 1 N. What is the force that the iron piece exerts on the magnet?
The iron piece exerts a force of 1 N divided by the ratio of the weight of the iron piece to the weight of the magnet in the same direction.
The iron piece exerts a force of 1 N on the magnet in the opposite direction.
The iron piece exerts a force of 1 N divided by the ratio of the weight of the iron piece to the weight of the magnet in the opposite direction.
The iron piece exerts a force of 1 N on the magnet in the same direction.
Answer:
the final statements the correct one is. The second
The iron piece exerts a force of 1 N on the magnet in the opposite direction
Explanation:
In this exercise they give us the force exerted by a magnet on an iron bar and ask us the force that the iron bar exerts on the magnet. We can see that these are action and reaction forces, which by Newton's third law must be of equal magnitude and opposite direction, each applied to one of the bodies.
the final statements the correct one is. The second
The iron piece exerts a force of 1 N on the magnet in the opposite direction
An electric field from a charge has a magnitude of 4.5 x 10^4 N/C at a certain
location that points outward. If another charge with a magnitude of -2.0 x 10^-6 C
is brought near it, what is the strength of the electrostatic force that acts on this
charge and how do the two charges behave?
0.09 N; repel each other
-0.09 N; attract each other
-2.3 N; repel each other
2.3 N; attract each other
Answer:
4.5 x 10^4 x -2 x 10^-6 = -0.09N
Explanation:
-0.09N
A skydiver falls toward the ground at a constant velocity. Which statement best applies Newton’s laws of motion to explain the skydiver’s motion? An upward force balances the downward force of gravity on the skydiver. The skydiver’s inertia is zero, which no longer allows for acceleration. An unbalanced force pulls the skydiver toward the ground. The mass of the skydiver is so great that there is no acceleration
Answer: A) an upward force balances the downward force of gravity on the skydiver
Explanation: I got it correct on my test on edge
The statement best applies Newton’s laws of motion to explain the skydiver’s motion an upward force balances the downward force of gravity on the skydiver. Thus, option A is correct.
Which statement best applies Newton’s laws of motion?
The statement that best applies Newton’s laws of motion to explain the skydiver’s motion is that an upward force balances the downward force of gravity on the skydiver. Newton's 3rd law often applies to skydiving.
When gravity is not acting upon the skydivers they would continue moving in the direction the vehicle they jumped from was moving. If no air resistance takes place, then the skydivers would still accelerating at 9.8 m/s until they hit the ground.
The skydiver after leaving the aircraft will accelerates downwards due to the force of gravity usually as there is no air resistance acting in the upwards direction, and there is a resultant force acting downwards, the skydiver will accelerates towards the ground.
Therefore, The statement best applies Newton’s laws of motion to explain the skydiver’s motion an upward force balances the downward force of gravity on the skydiver. Thus, option A is correct.
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what does grit mean in psychology
Answer:
The meaning of grit in psychology is a positive, non-cognitive trait based on an individual's perseverance of effort combined with the passion for a particular long-term goal or end state.
You have a hot reservoir held at 30°C and a cold reservoir held at 0°C. If you move 400 J of heat from the hot reservoir to the cold reservoir, what is the total change in entropy?
Answer:
Explanation:
Given the following :
Temperature (Th) of hot reservoir = 30°C (30 +273) = 303K
Temperature (Tc) of cold reservoir = 0°C (273K)
Quantity (Q) of heat transferred from hot reservoir = 400 J
Total change in entropy (ΔStotal) :
ΔStotal = ΔShot + ΔScold
ΔS = Q/T
Hot reservoir is losing 400J of heat ;
Q = - 400 J
ΔShot = Q/Th
ΔShot = - 400/303
ΔShot = - 1.32 J/K
ΔScold = Q/T
ΔScold = 400 / 273
ΔScold = 1.47 J/K
ΔStotal = ΔShot + ΔScold
ΔStotal = - 1.32 + 1.47
ΔS total = 0.15 J/K
Answer:
-400/303 = -1.32
400/273 = 1.47
-1.32 + 1.47 =
.15 J/K
Explanation:
a p e x
Rajah 9 menunjukkan laluan bagi kuching Fun Run. Berapakah sesaran bagi pelari tersebut? Mula 2 km 6 km Tamat 10 km Rajah Diagram 9 O A.5 km O B.6 km O c. 10 km D. 18 km
Answer:
jsjfj heddifii ididofi idididi hdhdii iridium didi buff joid duruvdudi 7u
Một xe chạy trong 2 giờ với tốc độ trung bình 45 km/h rồi chạy tiếp 4 giờ với tốc độ trung bình 40 km/h. Tốc độ trung bình của xe trong cả quá trình chuyển động đó gần giá trị nào nhất sau đây?
Answer:
hlo
Explanation:
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