Given :
Mass of box , m = 250 kg.
Force applied , F = 285 N.
The value of the incline angle is 30°.
the coefficient of dynamic friction is [tex]\mu=0.72[/tex] .
To Find :
The speed with which the box is moving with, assuming it takes 4 seconds to reach the top of the incline.
Solution :
Net force applied in box is :
[tex]F=285 - mgsin\ \theta - \mu mg cos \ \theta\\ \\F=285-mg( sin \ \theta - \mu cos\ \theta)\\\\F=285 - 20\times 10( \dfrac{1}{2}+0.72\times \dfrac{\sqrt{3}}{2})\\\\F=60.29\ N[/tex]
Acceleration , [tex]a=\dfrac{F}{m}=\dfrac{60.29}{20}=3.01\ m/s^2[/tex].
By equation of motion :
[tex]v=u+at\\\\v=0+3.01\times 4\\\\v=12.04\ m/s[/tex]
Therefore, the speed of box is 12.04 m/s.
Hence, this is the required solution.
Which refers to the ratio of output work to input work of a machine expressed as a percent?
total work
wattage
efficiency
power
Answer:
Efficiency Or C. on e2020
The ratio of output work to input work of a machine expressed as a percent refers to efficiency of the machine.
What is efficiency of machine?How well a machine converts its input energy into useable output energy, or work, is referred to as its efficiency. It is the portion or percentage of the output divided by the input, and it plays a significant role in a machine's utility.
It denotes the degree of performance that requires the fewest inputs to provide the greatest amount of output in more mathematical or scientific words. It frequently particularly refers to the ability of a particular application of effort to deliver a particular output with the least amount of waste, expense, or superfluous work. Efficiency covers a wide range of inputs and outputs across numerous disciplines and sectors.
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9. Which unit goes with time
kg
K
s
mm
Suppose you first walk 12.0 m in a direction 200 west of north and then 20.0 m in a direction 40.00 south of west. How far are you from your starting point, and what is the compass direction of a line connecting your starting point to your final position?
Complete Question
The complete question is shown on the first uploaded image
Answer:
the compass direction of the resultant displacement is [tex]\theta =4.7^o [/tex] south of west
Explanation:
Generally using cosine we can obtain the resultant R as follows
[tex]R^2 = A^2 + B^2 -2ABcos(70)[/tex]
=> [tex]R = \sqrt{12^2 + 20^2 - 2(12 ) * (20) cos 70}[/tex]
=> [tex]R = 19.48 \ m[/tex]
We can obtain the direction of the resultant by first using sine rule to obtain angle C as follows
[tex]\frac{A}{sin C} = \frac{R}{sin70 }[/tex]
=> [tex]C= sin ^{-1} [\frac{A * (sin 70)}{R} ][/tex]
=> [tex]C = sin ^{-1} [\frac{20 * (sin 70)}{19.48} ][/tex]
=> [tex]C = 74.7 ^o[/tex]
Then the direction is obtained as
[tex]\theta = C - 70[/tex]
=> [tex]\theta = 74.7 - 70[/tex]
=> [tex]\theta =4.7^o [/tex]
Hence the compass direction of the resultant displacement is [tex]\theta =4.7^o [/tex] south of west
What is a population?
Group of answer choices
A. a group of individuals of the same species living in the same area
B. a group of different species living in the same area
C. a group of individuals of the same species living in separated areas a group of different species living in separated areas
Answer:
A
Explanation:
Physics 1102 Experiment 5 Pre Lab Name_________________________________ Instructor name _________________________ You must show and explain all work in a neat and organized way to receive credit. Please show each step for calculations. YOU MUST TURN IN THIS SHEET. 1. (a) What does electrically neutral mean
Answer:
Explanation:
An atom is said to be electrically neutral, if the said atom contains equal or the same numbers of protons and electrons.
Worthy of note is that most bodies are normally close to being electrically neutral. This is because of the number of electrons on the body being equal to the number of protons on the same body. Charging a body means one would have to transfer electric charge to the body, or from the body. As a result, the number of electrons in the body will no longer be equal to the number of protons on the body.
For the system of Problem3.18, determine the amount of energy transfer by heat, in kJ per kg of refrigerant.[Problem3.18A closed, rigid tank contains a two‐phase liquid–vapor mixture of Refrigerant 22 initially at−20°Cwith a quality of 50.36%. Energy transfer by heat into the tank occurs until the refrigerant is at a final pressure of 6 bar. Determine the final temperature, in°C. If the final state is in the superheated vapor region, at what temperature, in°C, does the tank contain only saturated vapor?]
Answer:
35.625° C
Explanation:
See attachment
a) Final temperature is 35.625° C
b) 0°
When air sinks, it:_________
(a) compresses and warms.
(b) reaches its equilibrium level and then begins to sink.
(c) expands and cools.
(d) forms into clouds.
Answer:
a) compresses and warms.
Explanation:
When air sinks, it falls down and compresses the air close to the surface of the ground, which raises the temperature of the air (since compression results in a rise in temperature). Also, as the air sinks, it prevent the already warm air close to the surface from rising, further increasing its own temperature, warming it up.
A train is travelling east along a straight run of track at 54.0 km/hr. Inside, two siblings 1.90 m apart are playing catch directly across the aisle. The kid wearing a Catherine Wheel T-shirt throws the ball horizontally north. The ball crosses the train and is caught 1.05 s later by her little brother. (Ignore any effects of gravity or friction.)
a) Find the magnitude of the ball's velocity from the little brother's point of view.
b) What is the magnitude of the velocity of the ball as seen by someone standing still outside the train?
c) What is the angle between the direction of the ball and the direction of the train as measured by someone standing still outside the train?
Answer:
A.) 1.81 m/s
B.) 16.07 m/s
C.) 6.88 degree.
Explanation:
Given that Inside, two siblings 1.90 m apart are playing catch directly across the aisle. The kid wearing a Catherine Wheel T-shirt throws the ball horizontally north. The ball crosses the train and is caught 1.05 s later by her little brother.
The velocity of the ball will be
Velocity = displacement/ time
Where displacement = 1.90 m
Time = 1.05 s
Velocity = 1.9 / 1.05
Velocity = 1.8095
Velocity = 1.81 m/s
A.) From the little brother point of view, the magnitude of ball's velocity will be 1.81 m/s
B.) The magnitude of the velocity of the ball as seen by someone standing still outside the train will be achieved by first converting km/h to m/s
(54 × 1000) / 3600 = 15 m/s
Then, use pythagorean theorem to find the velocity
V = sqrt ( 15^2 + 1.81^2)
V = sqrt ( 225 + 3.2761)
V = sqrt ( 258.2761)
V = 16.07 m/s
C.) The angle will be
Tan Ø = 1.81 / 15
Tan Ø = 0.1206666
Ø = tan^-1(0. 1206666)
Ø = 6.88 degree.
Which principle(s) of the cell
theory shows that all organisms
are somehow similar?
Explanation:
The unified cell theory states that: all living things are composed of one or more cells; the cell is the basic unit of life; and new cells arise from existing cells.
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A sperm whale can accelerate at about 0.0800 m/s 2 0.0800 m/s 2 when swimming on the surface of the ocean. How far will a sperm whale travel if it starts at a speed of 0.700 m/s 0.700 m/s and accelerates to a speed of 2.18 m/s 2.18 m/s ? Assume the whale travels in a straight line.
Answer:
26.64 m
Explanation:
Given the following :
Acceleration at ocean surface = 0.0800 m/s²
Distance covered if initial speed = 0.700 m/s and accelerates to a speed of 2.18m/s
Using the equation :
v² = u² + 2as
Where ;
v = final velocity ; u = initial velocity ; a = acceleration ; s = distance covered
Therefore,
v² = u² + 2as
2.18² = 0.7² + (2 × 0.08 × s)
4.7524 = 0.49 + 0.16s
4.7524 - 0.49 = 0.16s
4.2624 = 0.16s
s = 4.2624 / 0.16
s = 26.64 m
What did Rutherford’s model of the atom include that Thomson’s model did not have?
a nucleus
energy levels
electron clouds
smaller particles
Answer:
Yes the answer is A.) A Nucleus
Explanation:
I took the test
Rutherford’s model of the atom included a nucleus that Thomson’s model did not have, therefore the correct option is A
What are atomic models?There are some models that are used to explain the arrangements of subatomic particles inside the atom based on the atomic theory of atom are known as the atomic models.
There are many types of atomic models proposed in past based on their individual assumptions and the experimentations
There are mainly five most widely accepted atomic models
John Dalton's atomic model which based on the assumption that all the entities of the universe are made up of the fundamental particle that is an atom.
J.J. Thomson's model: Plum Pudding model explains the arrangement of subatomic particles by taking the example of plum pudding in which positive charge is distributed uniformly throughout and the negative charge particles are sprinkled on it in a random fashion.
Rutherford's model explained the existence of a nucleus inside the atom by using the alpha particle bombardment experiment on a thin sheet of gold.
Niels Bohr's model explained the revolving nature of the electrons in the different shells around the nucleus of the atom.
Erwin Schrodinger's model explains the arrangement of the subatomic particles as the electron Cloud Model also known as the Quantum Model.
Rutherford’s model of the atom included a nucleus that Thomson’s model did not have, therefore the correct option is A
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