Answer:
2 hours
Explanation:
15 percent input work is lost due to friction,then what is the efficiency of machine?
Answer:
{ (x/y )*100 } - 0.15 y
Explanation:
The efficiency of a machine is the percent of output work divided by input work minus work lost from friction and heat.
Assume work output = x
Assume work input percent as =y
Work lost through friction is given as : 15% input work = 0.15 y
Then efficiency of the machine will be :{ (x/y )*100 }- 0.15 y
Use real values for x and y to find the correct efficiency of the machine.
The energy of electromagnetic waves increases with decreasing wavelength.
Which of the following statements support this claim?
O A. Dental patients need to wear lead aprons to protect themselves from X-rays but do not wear
protection from flashlights.
B. Both radio waves and gamma rays are invisible to human eyes.
C. Ultraviolet radiation causes sunburn but radio waves do not.
D. Microwaves are used for communication.
E. Gamma rays are used to kill cancer cells, but microwaves have no known effect on cancer
cells.
Answer: A C E
Explanation: i just did it and got it right lol
Answer:
its A, C, and E
Explanation:
i did it and got it right
What is the SI unit used to measure the temperature of a substance?
A. degree Celsius
OB
degree Fahrenheit
gram
OD
kelvin
ОЕ.
mole
Reset
Next
Answer:
Kelvin
Explanation:
Kelvin is the universal and scientific unit for temperature as Celsius and Fahrenheit temperatures we use in everyday situations
A box is suspended from a crane at a height of 32 m from the ground. The box has 7840 j of gravitational potential energy. What is the mass of the box
Answer:
The mass of the box is 24.97 [kg]
Explanation:
In order to solve this problem, we must use the concept of potential energy, which is defined as the product of mass by gravity by height. So we have the following equation.
[tex]E_{p} =m*g*h[/tex]
where:
Ep = potential energy [J]
m = mass [kg]
g = gravity acceleration = 9.81 [m/s^2]
h = elevation = 32 [m]
7840 = m*9.81*32
m = 24.97 [kg]
How do you measure the weigh of an object
Answer: Weight is a measure of the force of gravity pulling down on an object. It depends on the object's mass and the acceleration due to gravity, which is 9.8 m/s2 on Earth. The formula for calculating weight is F = m × 9.8 m/s2, where F is the object's weight in Newtons (N) and m is the object's mass in kilograms.
Answer:gravity pulling down on an object
Explanation:
The elevators in the Landmark Tower in Yokohama, Japan are among the fastest in the world. After starting from rest, they reach a maximum speed of 120 meters per minute. It takes the elevator 4.0 seconds to reach maximum speed. What is its acceleration in m/s/s (meters per second per second)?
Answer:
The acceleration is 30 m/s²
Explanation:
Given that,
Maximum speed = 120 m/s
Time = 4.0 sec
We need to calculate the acceleration
Using equation of motion
[tex]v=u+at[/tex]
Where, v = speed
u = initial speed
a = acceleration
t = time
Put the value into the formula
[tex]120=0+a\times4.0[/tex]
[tex]a=\dfrac{120}{4.0}[/tex]
[tex]a=30\ m/s^2[/tex]
Hence, The acceleration is 30 m/s²
In what direction must he walk in order to return to his original position?
30 degrees N of W
40 degrees N of W
40 degrees NW
50 degrees N of W
A rectangular field has one side fence 500m land and another side fond zoom
Answer:
40 dedrees south
Answer:
40 degrees south
Explanation:
An object is said to move from a position of 10m East to a position of 5m west. Determine the object's distance travelled.
Answer:
5 i think
Explanation:
answer these questions plz
1. The property of a conductor by virtue of which it posses the flow of electric current through it is called resistance.
2. The resistance of a conductor depends on the cross sectional area of the conductor and it's resistivity.
3.This id due to the fact that the resistance of a wire is inversely proportional to the square of its diameter.
4.Due to at high temperatures , the alloy donot oxidize. Alloy doesn't melt readily and get deformed.
An object at rest has equal forces acting on it. This can be described as a(n) _____________ force.
gravity
unbalanced
balanced
physical
When objects are charged by _______, they do not need to touch each other.
A.
friction
B.
induction
C.
conduction
D.
all of these
Answer:
B. Induction
Explanation:
Just had it on study island
When objects are charged by induction, they do not need to touch each other. Hence, option (B) is correct.
What are different process of charging?A charged particle is touched to a conductive medium as part of the charging by conduction process. In this manner, the conductor receives the charges from the charged substance.
Rubbing one particle against another causes electrons to move from one surface to another during the charging by friction process.
An object is charged using induction charging, which doesn't require physical contact between the charged objects. The charged particle is held close to an uncharged conductive substance that is grounded on a neutrally charged material during the charging by induction process.
When a charge is transferred between two objects, an uncharged conductive substance produces an oppositely polarized charge. These were the many charge transfer techniques.
Learn more about charges here:
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1 ) Starting from rest, a toy rocket accelerates at 12 m/sec/sec for exactly 4.0 seconds. It reaches 48 m/sec. Find the distance moved.
Which of these BEST explains how Earth's surface features are formed by moving tectonic plates? *
5 points
Earth's gravity acts as an opposing force, causing the crust to push upward, break into individual plates, and move along the surface.
The minerals in lithospheric plates are attracted to Earth's magnetic poles, which causes them to move along the surface.
The spinning of Earth's outer core causes the lithosphere to break into individual plates and collide with each other.
Earth's crust is separated into individual plates that float on top of molten material, convection currents in the mantle cause them to slowly move.
Answer: The spinning of Earth's outer core causes the lithosphere to break into individual plates and collide with each other.
Earth's surface forms because of this reason:
The spinning of Earth's outer core causes the lithosphere to break into individual plates and collide with each other.
Which answer best explains why clouds usually form high in the sky?
It is cool enough for the water vapor to begin condensing
It is warm enough for the water vapor to begin condensing
It is dry enough for precipitation to form from
it is dry enough for water vapor to form a cloud
Answer: As air rises the moisture in it slowly reaches its saturation point and when this happens, tiny crystals of water start to condense and form clouds.
Explanation:
A projectile is launched at an angle above the ground. (upwards). The vertical
component of the projectile's velocity is initially 30 m/s. What is the vertical velocity
after 2.0 seconds of flight?
A boy runs 400m at an average speed of 4.0m/s he runs the first 200m in 40 s how long does he take to run the second 200m?
if the boy runs 400m at an average speed of 4.0m/s he runs the first 200m in 40 at the same speed he will cover next 200m in 40 s and the the average speed is of 4.0m
What is angular speed ?Angular speed is a measures of speed of how fast the central angle of a rotating body changes with respect to given time
It mainly implies how quickly the object is rotating means it is described as the change in the angle of the object per unit of time.
To calculate the speed the value of angular speed are needed thus angular speeds formula is used to calculate the distance traveled by an object in terms of rotation and revolutions per unit of time.
The unit of angular speed of an object is denoted as radian per second and Both angular speed, angular velocity are calculated by using the same formula.
For more details speed, visit
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A stone is projected vertically upwards with a velocity of 30m/s from a tower of height 50m negleting air resistance,determine the maximun height it reached from the ground (g=10ms^-1)
A child blows a leaf from rest straight up in the air. The leaf has a constant upward acceleration of magnitude 1.0\,\dfrac{\text m}{\text s^2}1.0 s 2 m 1, point, 0, start fraction, start text, m, end text, divided by, start text, s, end text, squared, end fraction. How much time does it take the leaf to displace 1.0\,\text m1.0m1, point, 0, start text, m, end text upwards?
Answer:
Explanation:
Given
Acceleration a = 1.0m/s²
Displacement S = 1.0m
Required
Time t taken by the leaf to displace
Using the equation of motion
S = ut+1/2at²
Substitute
1.0 = 0+1/2(1)t²
1 = t²/2
Cross multiply
t² = 2
t = ±√2
t = 1.41secs
It takes the leaf to 1.41s to displace by 1m upward
How long does a dream typically last near the end of the sleep cycle, just before waking?
A.
about 5 minutes
B.
about 15 minutes
C.
about 30 minutes
D.
about 50 minutes
pleaseeeee hurryy
Answer:
C) about 30 minutes
Explanation:
edge 2023
What is the weight of a 4.5 kg mass on Earth?
Answer:
7.535×10^25 earth mass
Explanation:
for an approximate result,divide the mass value by 9.223e+18
what causes list development of a country ?why is Nepali still one of the least developed countries? write in points
True or False : the collect of evidence fall onto the detectives that arrive at a crime scene
Answer:true
Explanation:
A ball is dropped from the ceiling and free falls to the floor. Which one of the
following statements regarding the ball's motion is correct?
a. The ball speeds up as it falls to the ground.
b. The velocity of the ball is downward; uits value remains constant.
c. The velocity of the ball has a constant value of 9.8 m/s.
US 10:30
Answer:
A
Explanation:
Gravity
If you could solve one of
the world's greatest problems, which one would
you choose? Why did you choose this problem to
solve?
Answer:
the pollution
Explanation:
because is making big consecuences in the world
If I could solve one of the world's greatest problems, then I would like to choose pollution problem.
I would choose the pollution problem to be solved because it affects various natural resources of the environment.
Pollution is one the biggest issue in the world these days and It is rising day by day. It affects the environment directly or indirectly.
There are various types of pollution. Some of thees are
Water pollutionAir pollutionNoise pollution.The main cause of water pollution is various toxic substances got mixed in various water resources.
Similarly Air Pollution happens because of the harmful gases and substances present in the air.
Noise pollution occurs due to the sound of machines, loud musics and sound of vehicles.
Every human being should take steps to solve the issue of the pollution.
For more information about the pollution, follow the link given below.
https://brainly.com/question/1040743.
A man walks 30 ft. East, then 25 ft. South. How far is the man away from where
he started?
39.05 ft
32 ft
16.6ft
10ft
What are some examples of an element? How do you know they are an element?
HELP PLZ ITS DUE SOON
Does change in direction affect the acceleration of a car?
Answer:
A change in velocity is either a change in an object's speed or its direction. When a moving object changes direction, its velocity changes and it is accelerating.
Explanation:
A softball is thrown perfectly vertically (straight-up) at 18 m/s.
a) How high will it go?
b) Find the total time the ball is in the air.
Answer:
a) y = 16.51 [m]
b) t = 1.83 [s]
Explanation:
To solve this problem we must use two kinematics equations, the first to determine the height to which the ball reaches, and the second equation to determine how long it lasts in the air.
[tex]v_{f} ^{2}= v_{i} ^{2} - (2*g*t)\\[/tex]
where:
Vf = final velocity = 0
Vi = initial velocity = 18 [m/s]
g = gravity acceleration = 9.81[m/s^2]
t = time [s]
Note: the negative sign of the Equation indicates that the acceleration of gravity acts in the opposite direction to the movement of the ball. The final velocity is zero, since the ball reaches its maximum altitude when the velocity is zero.
Now replacing:
0 = (18)^2 - (2*9.81*y)
y = 16.51 [m]
b)
[tex]v_{f} = v_{i} - (g*t)[/tex]
0 = 18 - (9.81*t)
t = 1.83 [s]
The photo shows a person pumping gasoline into a car
Which TWO of these energy transformations will occur when the car’s engine starts?
A. Chemical energy —> thermal energy
B. Chemical energy —> mechanical energy
C. Mechanical energy —> Chemical energy
D. Thermal energy —> chemical energy
_____________________
Choose TWO
Answer:
It is CHEMICAL TO MECHANICAL because gas is a chemical which is transferred to mechanical technologies
Answer:
The first one is ^^
The SECOND one is chemical energy to thermal energy
You're welcome for getting wrong so that you can now get it right :|
carbon show some unique property name them name them
Answer:
Physical Properties of Carbon:
Carbon is a unique element. It occurs in many forms. Some examples of the pure form of carbon are coal and soot.
It is soft and dull grey or black in colour.
One of the most important compounds of carbon is the charcoal, which is formed when carbon is heated in the absence in of air.
It occurs in a number of allotropic forms. Allotropes are nothing but forms of an element with varying physical as well as chemical properties.
The density of the different forms of carbon depends upon the origin of these elements. You will find some forms of carbon which are pure and some forms which are not pure like coal which is the mixture of both carbon and hydrogen.
Chemical Properties of Carbon
Carbon compounds generally show 4 reactions, they are
Combustion reaction
Oxidation reaction,
Addition reactions
Substitution reaction.
As we all know that carbon in all forms needs oxygen, heat, and light and forms carbon dioxide. When it is burned in air to give carbon dioxide, it is called as combustion.
Let us get the concept of this using some examples when it is burnt in the air: When methane CH4 is burnt in the presence of oxygen it gives us carbon dioxide, heat, and light.
Explanation:
