Answer:
The magnitude of the coefficient of kinetic friction is approximately 1.304 × 10⁻⁵
Explanation:
The given parameters are;
The time it takes for the box to stop, "t" = 600 seconds
The distance the box moves before coming to a stop, "d" = 23 meters
The work done by the friction force to stop the block = The kinetic energy lost by the box
The work done by the friction force to stop the block = [tex]\mu _k[/tex]·m·g·d
The kinetic energy change of the block = 1/2·m·u²
Where;
g = The acceleration due to gravity = 9.8 m/s²
m = The mass of the box
[tex]\mu _k[/tex] = The coefficient of kinetic friction
d = The distance travelled by the block = 600 m
u = The initial velocity of the block
∴ [tex]\mu _k[/tex]·m·g·d = 1/2·m·u²
[tex]\mu _k[/tex]·g·d = 1/2·u²
[tex]\mu _k[/tex] = 1/2·u²/(g·d) = 1/2·u²/(9.8 × 23) = u²/450.8
∴ [tex]\mu _k[/tex] = u²/450.8...(1)
The kinematic equation of motion of the block can be presented as follows;
v = u - a·t
Where;
v = The final velocity = 0 m/s (The block slides to a stop)
u = The initial velocity
a = The acceleration of the block (the minus sign indicates that the block's velocity is decreasing)
t = The time of motion of the block = 600 seconds
Therefore, by substituting the above values, we have;
0 = u - 600·a
∴ u = a·600
The kinematic equation of motion for the distance moved by the block, "s" can be expressed as follows;
s = u·t - 1/2·a·t²
Where;
s = The distance moved by the bloc = 23 meters
∴ 23 = a·600·600 - 1/2·a·600² = 360,000·a - 1/2·a·360,000 = 180,000·a
a = 23/(180,000)
u = 600 × (23/(180,000)) = 23/300
The initial velocity, u = 23/300 m/s
From equation (1), we have;
[tex]\mu _k[/tex] = u²/(450.8) = (23/300)²/450.8 = 23/1764000 ≈ 1.304 × 10⁻⁵
The magnitude of the coefficient of kinetic friction, [tex]\mu _k[/tex] ≈ 1.304 × 10⁻⁵
what substance is used by plants as a source of food
Answer:
dart
Explanation:
dart and sun and water so that the plant be okay
Which is a possible result of higher air temperatures caused by global warming?
increase in sea level
freezing of polar ice caps
rapid evaporation of water in the soil
flooding of low-lying coastal areas
Answer: C. rapid evaporation of water in the soil :)
A possible result of higher air temperatures caused by global warming is rapid evaporation of water in the soil.
What is global warming and its causes and consequences?Global warming is a phenomenon that has been registered around the world during the last decades. It refers to a progressive increase in the average temperatures of the oceans and the Earth's atmosphere, which has consequences for flora and fauna, in addition to impacting critical sectors such as agribusiness.
Among the consequences of global warming are melting ice, rising sea levels, desertification, changes in rainfall, floods and reduced biodiversity.
See more about global warming at brainly.com/question/12908180
Hi I need help with this question (see image ).
Explanation:
a) Fixed points are the temperatures at which a thermometer is calibrated. They can refer either to the actual temperatures used for calibration, or the thermometer readings at those temperatures.
__
b) Fundamental interval is the difference between the fixed points. As with fixed points, it can refer either to the difference in actual temperature, or the difference in the corresponding thermometer readings.
Two spherical objects have masses of 200 kg and 500 kg. Their centers are separated by a distance of 25 m. Find the gravitational attraction between them.
Answer:
1.07 x 10⁻⁸N
Explanation:
Given parameters:
Mass 1 = 200kg
Mass 2 = 500kg
Distance of separation = 25m
Unknown:
Gravitational attraction between the two bodies = ?
Solution:
To solve this problem, we use the equation of the universal gravitation;
F = [tex]\frac{G mass 1 x mass 2}{r^{2} }[/tex]
G is the universal gravitation constant = 6.67 x 10⁻¹¹Nm²kg⁻²
r is the distance
Now insert the parameters and solve;
F = [tex]\frac{6.67 x 10^{-11} x 200 x 500 }{25^{2} }[/tex] = 1.07 x 10⁻⁸N
Given:
Mass of objects,
[tex]m_1 = 200 \ kg[/tex][tex]m_2 = 500 \ kg[/tex]Distance,
[tex]r = 25 \ m[/tex]We know,
[tex]G = 6.67\times 10^{-11} \ Nm^2/kg^2[/tex]As we know the relation,
→ [tex]F_G = \frac{Gm_1m_2}{r^2}[/tex]
By substituting the values, we get
[tex]= 6.67\times 10^{-11}\times \frac{200\times 500}{(25)^2}[/tex]
[tex]= 1.0672\times 10^{-8} \ N[/tex]
Thus the above answer is right.
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The current flowing through the heating element when a toaster is plugged into a 230V mains supply, if the element has a resistance of 265Ω.
Answer:
The current flowing the heating element is 0.868 amperes.
Explanation:
Ohm's law states that voltage is directly proportional to current. In other, words, we say that:
[tex]V \propto R[/tex]
[tex]V = i\cdot R[/tex] (1)
Where:
[tex]V[/tex] - Voltage, measured in volts.
[tex]i[/tex] - Current, measured in amperes.
[tex]R[/tex] - Resistance, measured in ohms.
If we know that [tex]V = 230\,V[/tex] and [tex]R = 265\,\Omega[/tex], then the current that flows through the heating element is:
[tex]i = \frac{V}{R}[/tex]
[tex]i = \frac{230\,V}{265\,\Omega }[/tex]
[tex]i = 0.868\,A[/tex]
The current flowing the heating element is 0.868 amperes.
At time=0s, the object is at the 21.0-meter position along the roadway. Where is the object at time = 10 s?
A) 91 m
B) 70 m
C) 140 m
D) 96 m
You are lifting a 15 kg weight. You lift the bar 0.25 m a total of 15 times.
a. What is the total height the bar was lifted?
b. What is the force needed?
c. What is the work done?
Explanation:
Given parameters:
Mass of the weight = 15kg
Height of bar lift = 0.25m
Number of times lifted = 15times
Unknown:
Total height the bar was lifted = ?
Force needed for the lift = ?
Work done = ?
Solution:
To solve this problem we need to understand that;
Work done = Force x distance
Work done = mass x acceleration due gravity x height
Work done = weight x height
a. Total height:
Total height = 0.25 x 15 = 3.75m
b. Force needed ;
Force needed = Weight of bar = mass x gravity
= 15 x 9.8 = 147N
So;
Force used for the 15 times = 15 x 147 = 2205N
c. Work done ;
Work done = weight x height = 2205 x 3.75 = 8268.75J
In which stage of sleep are you likely to experience hypnagogic
sensations of falling asleep
NREM-1 got this off a website
A bulldozer and a Mini Cooper are involved in a head-on collision. Which one experiences a greater force
Answer:
The mini Cooper will experience the greater force
Explanation:
Generally, a bulldozer has a greater mass compared to a Mini Cooper hence when both of these vehicles interact in an head on collision the Mini Cooper will experience a greater force because the bulldozer has a greater momentum
What are combined vectors that go in one direction?
A. equal in magnitude
B. one-dimensional
C. two-dimensional
D. displacements
Answer:
One-dimensional
Explanation:
What will most likely happen if a sound wave moves from the air through a solid?
It will increase in wavelength.
It will decrease in speed.
It will increase in speed.
It will decrease in wavelength.
WILL MARK BRAINLIEST!!!!!
How is the 3rd law different from the 1st and 2nd laws?
Answer:
In the first law, an object will not change its motion unless a force acts on it. In the second law, the force on an object is equal to its mass times its acceleration. In the third law, when two objects interact, they apply forces to each other of equal magnitude and opposite direction.
Explanation:
Maria is trying to meet her friends at the pool but construction is blocking her path from the parking lot directly to the pool. Because of this, she has to walk 20 ft. north, 35 ft. east, and then 20 ft. south to get to the pool. Find her distance and displacement.
Answer:75 ft east
Explanation:
A 240 kg crate full of bricks is pushed across a surface with an acceleration of 1.3
m/s2. If the crate travels a distance of 4.6 m, How much work is being done?
Answer:
Workdone = 1435.2N/m
Explanation:
Given the following data;
Mass = 240kg
Acceleration = 1.3m/s²
Distance = 4.6m
To find the force;
Force = mass* acceleration
Substituting into the equation, we have;
Force = 240 * 1.3
Force = 312N
Now, to find the workdone;
Workdone = force * distance
Workdone = 312 * 4.6
Workdone = 1435.2N/m
Find the centripetal force needed to keep an 60.0 kg rider traveling in a circle in the ride.
Given:
m=
V = (from part a)
R =
Unknown:
F=?
Equation:
F= m (y^2) / r
Explanation:
Given that,
Mass of the rider, m = 60 kg
Let the radius of the circle, r = 30 cm = 0.3 m
Let the velocity, v = 20 m/s
We need to find the centripetal force needed to keep the rider in a circular path. It can be given by :
[tex]F=\dfrac{mv^2}{r}\\\\F=\dfrac{60\times (20)^2}{0.3}\\\\F=80000\\\\\text{or}\\\\F=8\times 10^4\ N[/tex]
So, the required force is [tex]8\times 10^4\ N[/tex].
A resting state through the winter.
Adaptation: Bear sleeping in a cave during the winter months
0 A. Locomotion
B. Hibernation
C. Migration
D. Defense
Answer:
b
Explanation:
Bears hibernate in the winter
Does anyone know how to do this pleaseeeee
Answer:
See the answer below.
Explanation:
The latent heat of fusion is defined as the amount of energy needed to make a phase change from solid to liquid. And it can be calculated by means of the following expression:
[tex]Q_{fusion}=m*Dh[/tex]
where:
Qfusion = Heat Energy [J]
m = mass = 0.65 [kg]
Dh = latent heat fusion = 330000[J/kg]
[tex]Q_{fusion}=0.65*330000\\Q_{fusion}=214500[J][/tex]
2)
We know that energy can be calculated from power, where power is defined as the relationship between energy over time.
[tex]P=E/t[/tex]
where:
P = power = 60 [w]
E = energy [J]
t = time = 5 [min] = 300 [s]
[tex]E=P*t\\E=50*300\\E=15000[J][/tex]
The mass change due to the process is equal to:
[tex]m=282-274\\m=8[g]=0.008[kg][/tex]
Now using the following equation for the latent heat of Fusion, we can calculate this value:
[tex]Q=m*Dh\\Dh =Q/m\\Dh=15000/0.008\\Dh=1875000[J/kg][/tex]
Determine the mass of a boat that is propelled forward by a force of 1250N at an acceleration of 3 m/s2.
Answer:
416.6 KG
Explanation:
Due to the mass being missing from the equation you divide the force by the acceleration
Please I need help with this question (see image).
Show workings where necessary.
Answer:
Solution:
i) Heat supplied by heater = Heat gained by water = m * c*theta = 0.12Kg * 4200 * 10 = 5040Joules in 2 minutes.
ii) Power = Energy/time = 5040J/(2 * 60seconds) = 5040J/120seconds = 42Watts.
(iii) Heat supplied to the 70g of water = m * c * theta = 0.07Kg * 4200 * 9K = 2646J
(iv) Heat supplied by heater = Heat gained by 70g of water + Heat supplied to the metal vessel.
But,from our calculations above,
Heat supplied by heater = 5040J ......and
Heat supplied to the 70g of water = 2646J
.: substituting the values,we have that :
5040J = 2646J + Heat supplied to the metal vessel.
5040J - 2646J = Heat supplied to the metal vessel.
.: Heat supplied to the metal vessel = 2394J.
(v) Heat gained by metal vessel = Heat capacity of the vessel * theta.
2394J = Heat capacity of the vessel * 9K
.: Heat capacity of the vessel = 2394/9 = 266(Joule per Kelvin)
(vi) Using the formula:
Heat Capacity = mass * specific heat capacity
.: Specific heat capacity = Heat Capacity/mass = 266/0.55 = 484(Joules per Kilogram per Kelvin)
Explanation:
________❤️ hope it helps you ❤️__________Why do water molecules tend to stay together and hold their shape? Name and explain the phenomenon by which this happens
Answer:
because liquid and solid states of water possesses intermolecular force of attraction which held the molecules of water in fixed
pls guys what is the law of electrostatic
Answer:
hello
Explanation:
The magnitude of the electrostatic force of attraction or repulsion between two point charges is directly proportional to the product of the magnitudes of charges and inversely proportional to the square of the distance between them
9. Which is the type of force that causes acceleration?
a.balanced
b.zero
c.unbalanced
Explanation:
Answer:-Unbalanced Force causes acceleration.
But why?
This is because for accelerating a body we need unbalanced forces to move it.
Hope it helps :)
how much time will it take for a bug to travel 55 M across the floor if it's traveling by 1.1 m / s
Answer:
The bug will take 50 seconds to travel 55 m across the floor if it's traveling by 1.1 m / s.
Explanation:
Given
Distance covered by bug = d = 55 m
The speed = s = 1.1 m/s
To determine
Time the bug will take to cover the distance = t = ?
Using the formula to determine the time the bug will take to travel 55 m across the floor if it's traveling by 1.1 m/s.
Distance = Speed x Time
d = s x t
t = d/s
t = 55/1.1
t = 50 s
Therefore, the bug will take 50 seconds to travel 55 m across the floor if it's traveling by 1.1 m / s.
How does energy travel? Where is the initial source of energy in our solar system? What is the process that gives off energy from the sun called?
Answer:
How does energy travel?
One way the energy can travel is through radiation. An object can radiate energy in the form of electromagnetic waves, for example when a strong light is turned on and you can feel some heat coming from it, or when you walk under the sunlight and you can feel the heat in your skin.
Where is the initial source of energy in our solar system?
In the solar system, the source of energy comes from the Sun, and the sun irradiates that energy to all the nearby objects.
What is the process that gives off energy from the sun called?
The process is called radiation, this is all the energy that comes from the sun in the form of different electromagnetic waves (light in the visible range, UV rays, etc...)
Getting and using energy, reproducing, and maintaining structure are _______ of life.
If a person is walking along at 1.4m/s. How long will it take that person to walk one time around a high school track?
Answer:
285.7s
Explanation:
Given parameters:
Speed of the person = 1.4m/s
Unknown:
Time it takes to walk one time round the track = ?
Solution:
The circumference of the track is 400m for a standard pitch.
Now;
Speed = [tex]\frac{distance}{time}[/tex]
Time = [tex]\frac{distance }{speed }[/tex]
Now insert the parameters;
Time = [tex]\frac{400}{1.4}[/tex] = 285.7s
A boy and a girl are balanced on a massless seesaw. The boy has a mass of 75 kg and the girl's mass is 50 kg. If the boy sits 2.0 m from the pivot point on one side of the seesaw, where must the girl sit on the other side?
Answer:
The girl must sit 5 m on the other side of the seesaw.
Explanation:
Given;
mass of the boy, = 75 kg
mass of the girl, = 50 kg
distance of the boy from the pivot, = 2 m
let the distance of the girl from the pivot = d
<-------------2m-------------><-------------d-------------->
-----------------------------------------------------------------------------------
↓ Δ ↓
75 50
Apply the principle of moment, about the pivot;
clockwise moment = anticlockwise moment
75 x 2 = 50 x d
150 = 50d
d = 150 / 50
d = 3 m
The distance of the girl from the pivot is 3 m.
Therefore, the girl must sit ( 2m + 3m ) on the other side of the seesaw.
What is the temperature shown on the thermometer below?
A. 8 °F
B. 4 °F
C. –4 °F
D. –8 °F
Answer:
D, -8 F
Explanation:
This specific thermometer is in increments of two degrees per minor line and 10 per thicker line. Since the thermometer is showing below zero, the answer cannot be A or B since they are positive. -4 Cannot be the answer since the line addition does not make sense for that. It would be -4 if the thick line increments were 5 degrees instead of ten. Therefore if you count the lines by two from zero down to the thermometer line, you would get -8 Degrees F
Which statement about this figure is false
A. Line E represents a fault line.
B. Layer C is the youngest layer.
C. d,ike K is older than layer I.
D. The fault occurred after layer F formed.
The statement about the figure that is false is that d,ike K is older than layer I. That is option C.
What is cross-cutting relationships in geology?Cross-cutting relationships is a principle that when a body pass through different layers in geology, it is usually younger than all the layers it passed through.
That is to say that, d,ike K is younger than layer I, D and B which it passed through.
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Answer:
If it's not C then it HAS to be B.
Explanation:
By deductive reasoning.
a tree is blank relative to earth a tree is blank relative to the sun
hmmmmmmmmmmmmmmmmm ask someone else sorry if im not helping