A 3.5 kW drill transfers 5 000 kJ of kinetic energy during 15 seconds of use. What is the percentage efficiency of the drill?
Answer:
1.04%
Explanation:
Given that,
The power of drill = 3.5 kW = 3500 W
Transferred kinetic energy = 5000 kJ during 15 seconds of use.
We need to find the percentage efficiency of the drill. It can be given by :
[tex]\eta=\dfrac{P_o}{P_i}\times 100[/tex]
Where
Po and Pi are output and input powers.
[tex]P_o=\dfrac{5000\times 10^3}{15}\\\\=3.34\times 10^5\ W[/tex]
So,
[tex]\eta=\dfrac{3500}{3.34\times10^{5}}\times100\\\\=1.04\%[/tex]
So, the percentage efficiency of the drill is 1.04%.
A woman standing on the ground watches an airplane fly by a mountain on a clear summer day. Her reference point for the moving plane would be:
a. There is no reference point
b. The ground
c. The mountain
d. A person in the plane
Which part of the electromagnetic spectrum is typically used to make images based on the temperatures of objects?
X-rays
radio waves
infrared light
visible light
Answer:
Which part of the electromagnetic spectrum is typically used to make images based on the temperatures of objects?
X-rays
radio waves
infrared light<<<----- CORRECT
visible light
Explanation:
Edge 2021
Infrared light is typically used to make images based on the temperatures of objects.
What is meant by electromagnetic spectrum?The range of all EM radiation arranged from high to low frequency (short to long wavelength) according to their frequency or wavelength. is known as the electromagnetic spectrum (EM).
Here,
Similar to visible light, X-rays are a type of electromagnetic radiation. X-rays have a higher energy than light, on the other hand, and can penetrate most materials, including the human body.
Images of inside body tissues and structures are produced using medical x-rays.
Electromagnetic energy in the infrared region of the spectrum can be seen by them. There is a relationship between an object's temperature and the electromagnetic radiation it releases since infrared radiation is strongly related to object temperature.
Hence,
Infrared light is typically used to make images based on the temperatures of objects.
To learn more about electromagnetic spectrum, click:
https://brainly.com/question/15576247
#SPJ5
what is the difference between a meteor and a meteorite?
1. Meteors are larger than meteorites
2. Meteors come from the Kuiper belt and meteorites originate in the asteroid belt.
3. Meteors are more like comets than meteorites
4. a meteorite is a meteor that impacted the earth.
please help.
Answer:
meteorites, meteors are objects that enter Earth's atmosphere from space. But meteors—which are typically pieces of comet dust no larger than a grain of rice—burn up before reaching the ground. ... The term “meteorite” refers only to those bodies that survive the trip through the atmosphere and reach Earth's surface. I believe this is it
Which type of energy is water held back by a dam?
Answer: hydroelectric dams
Explanation: Enormous energy is stored in water held back by hydroelectric dams. The energy is transformed into (a form of kinetic energy) as it falls across the dam. The falling water strikes the blades of a turbine and makes them spin, and the then turns the shaft of a generator.
The answer is hydroelectric dams because Enormous energy is stored in water held back by hydroelectric dams. The energy is transformed into (a form of kinetic energy) as it falls across the dam.
Explanation: Please mark me as brainliest!
Do any of the atom diagrams below represent atoms of the same element?
Yes, all the atoms are the same element.
Yes, atom A and atom C are the same element.
Yes, atom A and atom B are the same element.
No, they are all different elements.
Atom A and atom C are the same element.
What is the the outermon shell with elections!
Answer:
Valence shell
Explanation:
The valence shell contains valence electrons
While driving his sports car at 20.0 m/s through a residential neighborhood, Royston
comes up behind a slow-moving grandma and decides to pass her on the left. If
Royston can accelerate at 6.00 m/s2, how long will it take for him to reach a velocity of
30.0 m/s?
Answer:
1.67s
Explanation:
Given parameters:
Initial velocity = 20m/s
Acceleration = 6m/s²
Final velocity = 30m/s
Unknown:
Time taken = ?
Solution:
Acceleration is the rate of change of velocity with time. It is mathematically expressed as;
Acceleration = [tex]\frac{v - u }{t}[/tex]
v is the final velocity
u is the initial velocity
t is the time taken
6 =[tex]\frac{30 - 20}{t}[/tex]
6 = [tex]\frac{10}{t}[/tex]
10 = 6t
t = 1.67s
what happens to the current in a circuit if the voltage applied is quadrupled and the resistance is cut in half?
Answer:
yhnjienfjknijeanfijawenkwamfjkamenkgtama4eikoatgjj
Explanation:
ga4tgaew4gtaegae4gaegae5tatgaeata54aetgaetg
A man ice skating in the skating rink at Campus Martius in downtown Detroit, has a mass of 75 kg and an acceleration of 4.5 m/s2 (without friction). How much force is the man exerting?
Answer:
337.5 N.
Explanation:
Force is equal to the law: m.a
where m: mass, a: acceleration
Why is NEWTON'S First Law of Motion often called the LAW OF INERTIA?
Answer:
According to newtons first law of motion an object remains in its state of rest or motion in a straight line unless an external unbalanced forces acts upon it. This is the reason why Newtons first law of motion is often called the LAW OF INERTIA
Why am i tall?I nee to know.
Answer:
If your parents are tall there's a big change you will be too, if your parents are short you'll be short. If you have a tall dad and a short mom you'll be in the middle of short and tall.
Explanation:
;)
In a series circuit, the current is _______
at every point around the circuit. Which of the following completes the sentence?
equal
different
In a series circuit, the current is _______
at every point around the circuit. Which of the following completes the sentence?
Answer:In a series circuit, the current is equal at every point around the circuit.
#CARRYONLEARNING #STUDYWELLAnswer:
The option that completes the sentence is;
Equal
Explanation:
A series circuit is a circuit arrangement whereby the components of the circuit are connected in a single chain by joining them end to end, thereby the current flows round the circuit through the singular path of the interconnected component in the circuit and therefore, the current which flows through each component as it flows round circuit, is equal at all points in the circuit.
Therefore, we have that in a series circuit, the current is equal at every point around the circuit.
In Florida, most of the rocks that are underground are a type of soft, white rock called limestone. If limestone is underwater for a long period of time, it begins to dissolve. Which of these processes most likely causes this change?
A. chemical weathering
B. erosion
C. deposition
D. physical weathering
In Florida, most of the rocks that are underground are a type of soft, white rock called limestone. Long-term submergence in water causes limestone to disintegrate. These processes most likely causes this change is called Physical weathering. Hence, Option D is the correct answer.
What is Physical weathering?Physical weathering is also known as mechanical weathering. It is the weakening of rocks followed by the disintegration due to the physical or mechanical forces including the actions on the rocks by the abrasion, frost chattering, temperature fluctuations and the salt crystal growth. Eventually, after many cooling and heating events, the rocks cracks and break into smaller pieces.
This same mechanical process applies when water freezes and thaws in the cracks of a rock. The chemical composition of the rock, however, remains the same in the process. In Florida, most of the rocks that are underground are a type of soft, white rock called limestone. Long-term submergence in water causes limestone to disintegrate.
These processes most likely causes this change is called Physical weathering. Hence, Option D is the correct answer.
To know more about limestone,
brainly.com/question/15148363
#SPJ2
A roller coaster begins at rest 120 m above the ground, as
shown. Assume no friction from the wheels and air, and that no energy is lost to heat, sound, and so on. The radius of the loop is 40 m. Find the speed of the roller coaster at points E and F.
Note:- Use g= 10 m/s2.
Answer:
B= 34.6 m/s
C= 49 m/s
D= 28.3 m/s
(i) 10 m (ii) 20 m (iii) 40 m (iv) 80 m
(c) The maximum potential energy of the object if its mass is 200g 1 mark
(i) 100 J (ii) 120 J (iii) 160 j (iv) 200 J
(d) In the given graph the total mechanical energy will be 1 mark
(i) Same (ii) increases (iii) decreases (iv) will be zero.
(e) In the given graph the kinetic energy 1 mark
(i) Same (ii) increases (iii) decreases (iv) increases then decreases.
Answer:
20m
420=80m
100
increases
increases then decreases
Which of the following agricultural advancements have had unforeseen adverse effects?
synthetic fertilizers wiping out nearby crops
irrigation causing damaging floods
hybrid plants causing cancer to consumers
use of pesticides increasing insect resistance
Answer:
use of pesticides increasing insect resistance
Explanation:
Pesticides are the chemicals used to kill or stop the growth of insects or pests in crops and plants.
Pesticides are used from a very long time and repeated use of same pesticide allowed insects to get use to of it and evolve themselves in a way that they become resistant to these pesticide, so pesticide do not have any effect on insects.
Hence, the correct answer is "use of pesticides increasing insect resistance".
Answer:
use of pesticides increasing insect resistance
Explanation:
A 30 kg child is in an elevator accelerating down at a rate of -5 m/s2.
a. Calculate the force of gravity on the child.
Answer:
The force is - 150 N
Explanation:
F = 30 • - 5 = - 150
A power plant has two types of transformers. The first type of transformer triples voltage and the second type of transformer reduces voltage by half. If both transformers have the same number of primary turns, how many secondary turns does the first type of transformer have?
a. 3/2 of the secondary turns in the second type of transformer
b. 1/6 of the secondary turns in the second type of transformer
c. 2/3 of the secondary turns in the second type of transformer
d. 6 times the secondary turns in the second type of transformer
Answer:
d . 6 times the secondary turns in the second type of transformer
Explanation:
In transformer , voltage is increased or decreased according to ratio of no of turns in secondary to no of turns in primary coil . The relation is as follows
V₂ / V₁ = n₂/n₁
n₁ and n₂ are no of turns in primary and secondary coil and V₁ and V₂ are voltage in primary and secondary coil.
for first type , Let no of turn in primary = n and no of turn in secondary = n₁
V₂ / V₁ = 3
so
n₁/n = 3
n = n₁ /3
n₁ = 3n
For second type , let no of turn in secondary = n₂
V₂ / V₁ = .5
n₂/n = .5
n₂ = .5n
n₂ / n₁ = .5n / 3n
n₂ / n₁ = 1 / 6
n₁ = 6n₂
option d is correct .
The population in the United States in 2015 was 321 million people. It is projected to increase to 438 million people by the year 2050.
If projections are true, the US population will increase
% from 2015 to 2050.
Answer:
Haven't done this but I think it will increase by 73.29% not too anyone correct me if I'm worng
Answer:
C) 20%
Explanation:
HURRY PLEASE!!
What are dichotomous keys used for?
Science
Answer:
Scientific tool used to identify organisms
Explanation:
Dichotomous keys consist of a series of statements with two choices in each step that will lead users to the correct identification.
I need help ASAPP
Thanks+ BRAINLIST only for correct answer for these questions.
Which among the following forms of electromagnetic waves has the highest frequency range?
O Microwave
O Radio waves
O X-ray
O Ultraviolet
Radio waves carry information from a broadcasting station to your radio or television.
-visible light
- sound
-X -ray
- gamma ray
Answer: For the first part the answer is Radio Waves and the second part’s answer is gamma ray.
A boy is running at -8 m/s and a girl running at -2 m/s. Who is running faster? How do you know?
Answer:
the girl is running faster because -2 is greater than -8
Explanation:
A .5kg book sits on top of a student's desk which is 9m high. How
much gravitational potential energy does the book have as it sits on the desk?
Answer:
441J
Explanation:
Given parameters:
Mass of book = 5kg
Height = 9m
Unknown:
Gravitational potential energy = ?
Solution:
The gravitational potential energy of a body is the energy due to the position of the body.
It is given as:
Gravitational potential energy = mass x acceleration due to gravity x height
Gravitational potential energy = 5 x 9.8 x 9 = 441J
A force of 50N is applied to a 6 kg object. What is the acceleration of the object?
Answer:
Should be 8.333 m/s^2
Explanation:
50/6 = 8.333
difference between input work and output work with table
Answer:
Explanation:
Input work is the work done on a machine as the input force acts through the input distance. ... Output work is the work done by a machine as the output force acts through the output distance. The machine does to the object to increase the output distance.
2. A science book is being pushed across a table. Can the book have a constant speed and a
changing velocity? Explain.
Which is NOT an example of unbalanced forces acting on an object
A.an acorn falling from a tree
B.a car traveling straight down a road at 40km/h
C.a motorcycle changing speed from 20km/h to 35km/h
D.a truck slowing down as it approaches a red light
Answer:
C. a motorcycle changing speed from 20km/h to 35km/h
Explanation:
The choice not showing unbalanced forces acting on the object is a motorcycle changing speed from 20km/h to 35km/h.
This change in velocity shows that the body is accelerating during the time interval.
When a body is accelerating, it is changing it's motion and this implies that some unbalanced forces are acting in the body. Unbalanced body changes the state of motion of a body from rest to acceleration or deceleration as the case may be.
Which of the following is a measurement of velocity?
A)16 m east
B) 55 m/h south
C) 25 m/s2
D) 60 km/h
Answer:
B) 55 m/h south
Explanation:
Velocity is the rate of displacement per unit of time.
It is mathematically expressed as:
Velocity = [tex]\frac{displacement}{time}[/tex]
Displacement is the distance covered by a body in a specific direction.
Velocity is different from speed in that it specifies the direction of a body as it travels.
Therefore, we say, velocity is a scalar quantity.
When we are giving velocity values, the unit is expressed with the direction also delineated.
From the given choices, the unit with the south direction and meter per hour is obviously correct.
which of these statements describe friction