Answer:
Fastening-run & High-Jumping
A 25 kg sled is pulled across a horizontal surface by a 200 N force at a constant velocity. What is the coefficient of friction between the sled and the surface?
Answer:
0.82
Explanation:
constant velocity.means acceleration a = 0, so net force = 0
F - μmg = ma = 0
so μ = F/(mg) = 200/(25*9.8) = 0.82
( 25 POINTS )There is a light pole on one bank of a small pond. You are standing up while fishing on the other bank. After reflection from the surface of the water, part of the light from the bulb at the top of the pole reaches your eyes. Use a ray diagram to help find a point on the surface of the water from where the reflected ray reaches your eyes.
Determine an expression for the distance from this point on the water to the bottom of the light pole if the height of the pole is H , your height is h , and the distance between you and the light pole is L .
You must answer in terms of these varibles.
Following the Law of reflection we can assume that the expression for the distance from the point of reflection on the water to the bottom of the light pole is d = (H (L-d)) / h.
What does the Law of Reflection state?
The Law states that the reflection angle -θ₂- of an incident ray on a reflecting surface will be equal to the incidence angle -θ₁- of that ray.
Both angles, the reflection and the incidence one, are measured conserning the normal to the surface.
The law of reflection derives from Fermat's principle and states that the triangle formed between the incident ray and the surface, and the triangle produced by the reflected light and the surface are the same.
In the exposed example, if
H is the height of the pole,h is the height of the person,L the distance from the person to the pole,d is the distance from the pole to the point of reflection,L - d is the distance from the person to the point of reflection.If,
θ₁ = θ₂
h/L-d = H/d
Then, the distance from the point of reflection on the water to the bottom of the light pole, d is
d = (H (L-d)) / h
In the atached files you will find the diagram.
You will learn more about the Law of Reflection at
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In rock climbing, various rope and pulley systems have been devised to help haul up heavy loads, including injured climbers. A rescuer is hauling up an injured climber who weighs 930 N using the rope and pulley system shown in (Figure 1). (The ropes in this figure are drawn at various angles for clarity, but you can assume they're all vertical.) What is the tension in rope 1, the rope that the rescuer pulls on? What is the tension in rope 2?
The tension in ropes 1 and 2 is mathematically given as
a)T1=310N
b)T2=610N
What is the tension in ropes 1 and 2?Question Parameters:
A rescuer is hauling up an injured climber who weighs 930 N
Generally, from the diagram, we see that the respective Tensions is mathematically given as
T2=2T1
Where
T1+T2=930
3T1=930
T1=310N
In conclusion, the tension in rope 2
T2=2T1
T2=2*310
T2=610N
Read more about Tension
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Calculate the average acceleration of a car that changes speed 0 m/s to 15 m/s in 5 s
Answer:
Explanation:
average acceleration= (15-0)/5
=15/5
3ms-2
WHAT MUST BE APPLIED FOR AN OBJECT TO CHANGE ITS MOTION?
Answer:
Force
Explanation:
An applied force affects the motion of an object. An applied force can be a push, pull, or dragging on an object.
- profparis
Evaluate the powers of 3 to find each value. What is the value of 3-2 What is the value of 30 What is the value 31 What is the value of 33
Answer:
3^-2 is 1/9
3^0 is 1
3^1 is 3
3^3 is 27
Answer:
1/9
1
3
27
Explanation:
Which of the following is the most appropriate description of an electric current?
A hurricane that has winds between 74 and 95 miles per hour and causes some damage would be classified as a Category _______ storm.
1
3
2
4
Answer:
Category 1
Explanation:
I hope this helps
Answer: CAT-1
Explanation:
The flywheel of a steam engine begins to rotate from rest with a constant angular acceleration of 1.27 rad/s^2. It accelerates for 27.5 s, then maintains a constant angular velocity. Calculate the total angle through which the wheel has turned 66.1 s after it begins rotating.
With a constant angular acceleration of 1.27 rad/s^2 and acceleration of 27.5 s, is mathematically given as
[tex]\theta = 1848 radians[/tex]
What is the total angle through which the wheel has turned 66.1 s after it begins rotating?Generally, the angular velocity is mathematically given as
w2 = 0 + 1.27*27.9
w2 = 35.43 rad/s
Therefore
[tex]\theta1 = 0.5*1.27*27.9*27.9[/tex]
[tex]\theta2 = w2*(66.1-27.9)\\\\\ \theta = \theta1 + \theta2[/tex]
[tex]\theta = 1848 radians[/tex]
In conclusion, the total angle is
[tex]\theta = 1848 radians[/tex]
Read more about Angle
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Sally is investigating electromagnets. She is going to change the number of turns on the coil of
wire and investigate how this affects the strength of the electromagnet.
a I Name one variable Sally must keep the same each time she tests her electromagnet.
Answer:
The number of turns in a coil
Explanation:
A rock is thrown vertically up and reaches a maximum height of 20m. What was its initial velocity?
Answer:
Solve it simply,
Vi = 20 m /sec
Vf = 0 ( at max. height)
g = - 9.8 m/ sq. sec. ( -ve sign shows that the motion of the body is in opposite direction to that of gravity)
Height it gains=h = ?
time taken by the body=t=?
Using 3rd equation of kinematics,
2gh=Vf ˄2 – Vi˄2
implies that
h = Vf ˄2 – Vi˄2 / 2a
h = 0˄2 - (20)˄2 / 2(-9.8) = - 400/ -19.6
h = 20.4 m
So the maximum height the body can gain is approximately equal to 20.4 m.
Now , using 1st equation of kinematics:
Vf = Vi + at implies that,
t = Vf - Vi/g = 0 - 20/ - 9.8 = 2.04 sec.
So, it will take 2.04 sec. to get the max. height.
Note: in simple approximation if we take g =- 10 m/ sq.sec then the max. height the body can attain will be 20 m and the time required for it, is 2 sec.
What is an isotope?
A) Atoms of the SAME element that have different numbers of NEUTRONS.
B) Atoms of DIFFERENT elements that have different numbers of NEUTRONS.
C) Atoms of the same elements that have DIFFERENT numbers of PROTONS.
D) Atoms of the DIFFERENT element that have DIFFERENT numbers of PROTONS.
Please help me!!
:)
10 Points!
Answer:
A
Explanation:
they are atoms of the same element that have the same number of protons but different number of neutrons.
The 3 important steps to a perfect forehand in tennis are : perfect swing, type of racket, and correct finish
Question 1 options:
True
False
Answer:
False
Explanation:
The 3 important steps to a perfect forehand in tennis are Preparation,Backswing and Swing and contact.
There are two bulb with different watts. A bulb has heigher wattage than B.
Which will shine brighter in :-
series
parallel
what is photography ??
Answer:
Photography is the art, application, and practice of creating durable images by recording light, either electronically by means of an image sensor, or chemically by means of a light-sensitive material such as photographic film.
Explanation:
In the definition of photography:
the art or process of producing images by the action of radiant energy and especially light on a sensitive surface (such as film or an optical sensor)
Purpose of photography:
To communicate and document moments in time.
Explanation:
When you take a photograph and share it with others, you're showing a moment that was frozen through a picture. This moment can tell someone many things, from the environment to what people are doing.
Hope this helps you.
Answer:
It's an art or an application of clicking photos .
can someone solve this ?
Explanation:
calculate the applied force in N.
Which statement best describes how the phase of the Moon changes from a nev, moon to a
а
full moon?
The phase of the Moon changes from new Moon to a full Moon when the Moon moves around the earth until it is between the Sun and the Earth.
What is the Moon?The moon is a large massive body which is found in orbits around the earth.
The moon is said to be the satellite of the earth and orbits the earth in the form of a moon cycle or phases.
The moon cycle occurs when the move moves around the earth from the full moon to a new moon.
Therefore, the phase of the Moon changes from new Moon to a full Moon when the Moon moves around the earth until it is between the Sun and the Earth.
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#SPJ1
Jhen swam 3 complete laps in a 70 meter pool. (1 lap is one length of the pool)
The total distance covered by Jhen is 210 m and the total displacement is zero (0).
Distance covered by JhenThe total distance covered by Jhen is calculated as follows;
D = 70 m x 3 (since 1 lap is equal to one length of the pool = 70 m)
D = 210 m
Displacement of JhenThe displacement of Jhen is the change in the final position and the initial position of Jhen.
After 3 laps, the final position = the initial position
Displacement = 0
Thus, the total distance covered by Jhen is 210 m and the total displacement is zero (0).
The complete question is below:
Find the total distance and displacement of Jhen.
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if earth would stop receiving heat and light about 8 min what happen
If the Sun disappeared suddenly, we wouldn't know about it for about 8 minutes ... that's how long it takes for heat and light from the Sun to get here to Earth.
8 minutes after the Sun disappeared, the sky would turn totally black. All plants would immediately stop growing ... including all the plants that people or animals eat to live.
Then, after a few more minutes, we would start to notice that it was beginning to slowly get cooler, and that would continue until Earth was too cold for anything to live on it.
How would a speed bump change the results of a car collision - Newtons Third Law
Answer:
the speed bump would slows down the car 40% of most vehicles. speeding cars would deterred. this would result in fewer accidents.
A mouse of mass 200 g falls 100 m down a vertical mine shaft and lands at the bottom with a speed of 8.0 m/s. During its fall, how much work is done on the mouse by air resistance?
The work done on the mouse by air resistance is equal to 196 Joules.
Given the following data:
Mass = 200 grams to kg = 0.2 kg.
Distance = 100 meters.
Scientific data:
Acceleration due to gravity = 9.8 [tex]m/s^2[/tex]
How to calculate work done.In Science, work done is generally calculated by multiplying force and the vertical distance or displacement experienced by an object.
Mathematically, work done is given by the formula:
[tex]Work\;done = force \times displacement = mgh[/tex]
Substituting the given parameters into the formula, we have;
[tex]Work\;done = 0.2 \times 9.8 \times 100[/tex]
Work done = 196 Joules.
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A solenoid has 450 loops, each of radius 0.0254 m. The field increases from 0T to 3.00 T in 1.55 s. What is the EMF generated in the coil?
Answer:
-1.76
Explanation:
emf=-1.76V
help me please
explain how to do this if you can
Answer: x = 128°
180° - 52° = 128°
Answer:
128 degrees
Explanation:
A circle has a degree of 360, all around. You can imagine a circle, with the center being where the line intercepts the right angle.
360 = 52 + 38 + 142 + x
360 = 232 + x
128 = x
A ball is moving up a hill at 20 meters per second, and is decelerating at a uniform rate of 2 meters per second squared. What is its velocity after 5 seconds? Assume the direction up the hill is positive.
Answer:
-12meters per secondExplanation:
2^5=32-20=-12 meters per sec (going backwards).
If this is correct pls mark me. brainly to let me know, tyy C:
what is the total time that the bullet is in contact with the board?
Answer:
an acceleration of the boy as it passes through the board and be the total time the boy is in contact with the board solution
4. Find the period of a pendulum that is 1.2 m long.
Answer:
2.20 s
Explanation:
[tex]T=2\pi\sqrt\frac{L}{g}=2\pi\sqrt\frac{1.2}{9.8}}[/tex]
T = 2.20 s
A horizontal uniform bar of mass 2.5 kg and length 3.0 m is hung horizontally on two vertical strings. String 1 is attached to the end of the bar, and string 2 is attached a distance 0.6 m from the other end. A monkey of mass 1.25 kg walks from one end of the bar to the other.
Required:
Find the tension T1 in string 1 at the moment that the monkey is halfway between the ends of the bar.
Answer: I am not sure if you wanted me to answer this or not.
Explanation:
1. A projectile massing 2000 kg is launched at a 42 degree angle to the horizontal with initial velocity of 1000 m/s. Ignoring air resistance:
a. find the range
b. find the max height
c. find the time of flight
find the image of (4 "-1)" obtained by translating 4 units up followed by a reflection over the y-axis
Answer:(-4,3)
Explanation: They didn’t show the whole graph so it looks confusing but it’s not.
Which of the following factors affect the motion of an object? (Select all that apply.)
the mass of the object
the friction involved
the gravity pulling on the object
the amount of force applied to the object
Answer:
The mass of the object.
The friction involved.
The amount of force applied to the object.
The gravity pulling on the object.
Explanation:
I think that all answers are correct with the right explanation.
the mass is what is pulled on by gravity to determine weight.
friction opposes motion.
gravity pulls everything to the earth's centre
force makes an object to either stop, change direction or increase the velocity of an object depending on the amount.