Science: Work, Power and Efficiency Practice Problems:

Work = Force x Distance
Power = Work / Time
Percent Efficiency = Work
Output/Work Input x 100

Step 1: Write the equation
Step 2: Substitute with units
Step 3: Solve with units
rounding to the nearest tenth

1) It took 639 Newtons to push a table 21 meters. How much work was done?

Answers

Answer 1

Answer:

I believe it is 13,419 joules.

Explanation:

I could be very wrong, please fact check me


Related Questions

Explain What the core muscles do and why it's important to have a strong set of core muscles.​

Answers

Answer: Core muscles protect the spine and keeps it stabilized. Also they can help control movements such as walking and standing. The core helps transfer energy and help us move in different directions. It's important to have a strong set of core muscles.

Explanation:

Answer:

The core muscles stabilize and protect the spine. They help control all movements and make it possible for us humans to walk and stand up right. The core helps us transfer energy, shift our body weight and reach/move in different directions. It is important to have a strong set of core muscles because it makes everyday activities easier.  

Explanation:

what is the magnitude of velocity for a 1500 kg car possessing 4500 kgm/s of momentum?

Answers

It would have to be 3,75m/s

A force of 900 N pushes a wedge 0.10 m into a log. If the work done on the log is 50 J, what is the efficiency of the wedge?

Answers

Answer:

I'm fairly certain it's 1,800

Explanation:

The efficiency of the wedge with force F=900 N displaces the wedge 0.10 m is 55.55%  or 56%.

What is the efficiency of the machine?

The efficiency of the machine equals the ratio of output energy and input energy. It is also defined as the ratio of work done on a load by the machine to the work done on the effort by the machine.

A load is defined as the weight lifted by the machine. The effort is defined as the force applied to bring the desired change in the load. Work done is defined as the product of force and displacement.

The efficiency, η = Output power / Input power, and the highest efficiency of the machine is equal to one. The efficiency of the machine has no unit. The efficiency η = (Actual work done / Ideal work done) × 100.

From the given,

Force = 900 N

Displacement = 0.1 m

Work done = F × s = 900×0.1 = 90 J

Actual work done = 50 J

Efficiency,η = (50/90) × 100

           η  = 55.55 %

Thus, the efficiency of the wedge is 55.56%.

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A car drives in a circle at 56 km/hr. Which of
the following accurately describes the
motion of the car? The car's -
speed and velocity are both constant.
velocity is constant but speed is changing.
speed is constant but velocity is changing.
speed and velocity are both changing.

Answers

Answer:

Speed is constant but velocity is changing

Explanation:

Speed is a scalar quantity, meaning magnitude only. Velocity is a vector quantity, meaning magnitude and direction. If you're moving in a circle at a constant speed, the speed is constant but the direction is constantly changing. Therefore, the speed is constant but velocity changes.

HELP NEEDED ASAP GIVING BRAINLIEST!!

View the video clip below and answer the question.

The video clip above illustrates the process of __________

Answers

Exploding planet or astroifd

A car accelerates from 20.0 m/s to 28.0 m/s over a distance of 50.0 m. What is the car’s acceleration?

Answers

Answer:

Explanation:

[tex]V^2=V^2_o+2a(x_f-x_i)[/tex]

[tex]28^2=20^2+2a(50)\\784=400+100a\\384=100a\\a=3.84m/s^2[/tex]

what are food sorces of iron​

Answers

Answer:

liver (but avoid this during pregnancy)

red meat.

beans, such as red kidney beans, edamame beans and chickpeas.

nuts.

dried fruit – such as dried apricots.

fortified breakfast cereals.

soy bean flour.

Explanation:

what is refractive index ? ​

Answers

refractive index of a material is a dimensionless number that describes how fast light travels through the material

Explanation:

Refractive Index is a value calculated from the ratio of the speed of light in a vacuum to that in a second medium of greater density. The refractive index variable is most commonly symbolized by the letter ‘n’ or n’ in a descriptive text and mathematical equations.

Sodium and phosphorus combine to form Na3P. What is the name of this compound? phosphorus sodiate phosphorus sodide sodium phosphate sodium phosphide

Answers

Answer:

Sodium phosphide

Explanation:

Answer:

sodium phosphide

Explanation:

i just took the test. Good luck!! Have a great day!!

what are the standard units of displacement?

Answers

the answer is meters....I think??

The net force acting on this object is 200N to the left. What is the force of friction and air resistance combined if the thrust force is 500N?

Answers

Answer:

Explanation:

Force of friction and air resistance  acts against the external force . Let it be f .

net force = external force - frictional force and air resistance

Putting the given values

200 = 500 - f

f = 500 - 200 = 300 N .

Hence force of friction = 300 N .

Plz help me plzzz. I'm begging you

Answers

Answer:

a then c then b

Explanation:

PLEASE HELP I'LL MARK BRAINLIEST ​

Answers

Answer:

B

Explanation:

Please help!! This is due today!!

A shopping bag can provide a force of 65 N before breaking. A shopper puts 5 kg of groceries in the bag. If the shopper tries to lift the bag with an upward acceleration of 2 m/s/s, will the bag break?

Answers

No I don’t think so
Fg= mg
Fg= 5kg• 9,8kg/N
Fg= 49 N

How long will it take a rocket traveling at 8km/s to reach 20 km?

Answers

Answer:

2.5 seconds

Explanation:

20:8= 2.5 seconds

have a nice day! (^o^)

Answer:

2.5 seconds

Explanation:

20 ÷ 8 = 2.5

That's it.

How can a volcano develop in the middle of a tectonic plate?

Answers

Answer:

Volcanoes that form away from plate boundaries are created by hotspots. A hotspot is an area in the mantle that is believed to be somewhat hotter than the surrounding material. The rising magma from the hotspot can push its way through the crust and burst out at the surface, forming a volcano.

Explanation:

Volcanoes can form in subduction zones, which are regions where tectonic plates are interacting one and plate is sinking beneath the other.

Essay about how volcanoes form.

A volcano is a hill or mountain in the shape of a cone that is erected around a fissure in the surface of the earth thru which heated gases, rock fragments, and lava are released. A conical mass grows around the conduit as the solid fragments gather there, becoming progressively larger until it reaches the size of a gigantic volcanic mountain.

Explain what a volcano is.

A volcano is an aperture or vent through which magma, tephra (small rocks), or steam are released onto the the planet's surface. Days, weeks, or even years might pass between outbursts of volcanoes.

To know more about : development of volcano

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A projectile is shot horizontally from the edge of a cliff, 400 m above the ground. The projectile is traveling horizontally at 65 m/s the moment it leaves the cannon.

What is the initial vertical velocity of the projectile?

Determine the time taken by the projectile to hit the ground.

How far does the projectile land from the base of cliff?

Find the vertical component of the velocity just before the projectile hits the ground.

What is the magnitude of the final vector velocity the instant before it hits the ground?

What is the direction of the final vector velocity the instant before it hits the ground?

Answers

Answer:

a)  [tex]v_{oy}[/tex] = 0,  b)  t = 9.035 s, c) x = 587.275 m, d)  v_y = -88.54 m / s,

e) v = 109.84 m / s,  f)  θ = -53.7º

Explanation:

This exercise is a projectile launch

a) as the projectile is launched horizontally, its initial vertical velocity is zero

          [tex]v_{oy}[/tex] = 0

b) let's use the relation

          y = y₀ + v_{oy} t - ½ g t²

when reaching the ground y = 0 and the initial vertical velocity is v_{oy}=0

         0 = y₀ + 0 - ½ g t²

         t = [tex]\sqrt{ \frac{2 v_o}{g} }[/tex]

         t = [tex]\sqrt{ \frac{ 2 \ 400 }{ 9.8} }[/tex]

         t = 9.035 s

c) the horizontal distance is

         x = v₀ₓ t

         x = 65  9.035

         x = 587.275 m

d) the vertical speed when touching the ground

         v_y = [tex]v_{oy}[/tex] -gt

         v_y = 0 - 9.8 9.035

          v_y = -88.54 m / s

the negative sign indicates that the velocity is directed downwards

e) the velocity at this point

          v = [tex]\sqrt{ v_x^2 + v_y^2}[/tex]

          v = [tex]\sqrt{65^2 + 88.54^2}[/tex]

          v = 109.84 m / s

f) the direction of the velocity

let's use trigonometry

          tan θ = v_y / vₓ

          θ = tan⁻¹1 v_y / vₓ

          θ = tan⁻¹ (-88.54 / 65)

          θ = -53.7º

this angle is measured clockwise

is 468km per minute describing speed or velocity

Answers

velocity probably well that’s what i would put

loop od death cause and effect​

Answers

Answer:true

Explanation:

Which metric prefix has a decimal form of 0.01?​

Answers

Answer:

Centi is the metric prefix for 0.01

Describe a way that gravity influenced the formation of the solar system, with the planets orbiting the sun.

Answers

Newton realized that the reason the planets orbit the Sun is related to why objects fall to Earth when we drop them. The Sun's gravity pulls on the planets, just as Earth's gravity pulls down anything that is not held up by some other force and keeps you and me on the ground.

Gravity influenced the formation of the solar system, with the planets orbiting the sun.

What is Gravitational Force ?

Gravitational force is force of attraction between two masses. Gravitational force(F) between two bodies is directly proportion to the product of masses(m₁,m₂) of two bodies and inversely proportional to square of distance(r) between them. mathematically it is written as,

F [tex]\alpha[/tex] m₁.m₂

F [tex]\alpha[/tex] 1/r²

F = G m₁,m₂÷r²

where G is gravitational constant, whose value is 6.6743 × 10⁻¹¹ m³ kg-1s⁻².

Force is expressed in Newton N in SI unit. its dimensions are [M¹L¹T⁻²].

According to Kepler's first law of motion, every planet is moving in an elliptical orbit with sun has situated at one of the foci of the orbit.

when a planet moves in the orbit around the sun, it moves in a stable orbit. in this orbit , centripetal force is equal to centrifugal force, in this case centripetal force appears as gravitational force. Means Gravitational force between sun and planet balances the centrifugal force which is outwards. In such a way gravity influenced the formation of the solar system.

Hence gravity plays crucial role in the formation of solar system.

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How are reversibility, time, and entropy connected

Answers

Answer:

As one goes "forward" in time, the second law of thermodynamics says, the entropy of an isolated system can increase, but not decrease. ... Thus, entropy measurement is a way of distinguishing the past from the future.

Explanation:

Which of the following objects have gravitational potential energy?
A) a diver standing on a diving platform.
B) A hockey puck gliding across the ice.
C) an archers bow that is drawn back.
D) A runner waiting on the starting blocks.

Answers

Answer:

An archers bow that is drawn back

Answer:

A)a diver standing on a diving platform.

REQUESTS/REQUIERMENTS:

BRAINLIEST PLEASE

Can y’all help me pleaseeee

Answers

it would still be 5
the answer is five, hope you have a good one!

[WASSCE June 2008 Qu 11]
[
A force of 20 N acts at an angle of 30° to the
horizontal. Determine the vertical component
of the force.
A. 17.30 N
B. 11.50 N
C. 10.00 N
D. 7.50 N
[WASSCE Nov 2008 Qu 11​

Answers

α=30°

F=20 N

Fh=F*cos(α)

Fv=F*cos(90-α)=F*sin(α) (vertical component of the force F)

Fv=20*0,5=10.00 N

Answer (C)

What unit of time on Earth is based on the revolution of the Earth around the Sun?
A.
day
B.
hour
C.
year
D.
month

Answers

C.) Year

i hope this helped! please mark me as brainliest and 5 stars >:)

Answer:

I believe it's C. Year.

Explanation:

Hope this helps! ^^

You drop a rock down a well that is 31 m deep. How long does it take the rock
to hit the bottom of the well?
A. 1.9 s
B. 2.7 s
C. 6.3 s
D. 2.5 s

Answers

It’s (A) I’m not really sure

An object accelerates at 8 m/s^2 when a force of 40 Newtons is
applied to it. What is the mass of the object? (Use formula: m=Fla)

Answers

Answer:

5 kg

Explanation:

Acceleration = 8 m/s^2

Force = 40 N

Force = mass * acceleration

mass = force / acceleration

mass = 40 / 8

mass = 5 kg

1) Li + ČI>LICI
How many atoms are in this?

Answers

Answer:

2 atoms

Explanation:

Please help!!!

What do all of the inventors discussed in this lesson have in common?
All of the inventors can be characterized as problem-solvers.
O All of the inventors created new things as children.
All of the inventors used engineering principles to create new things.
O All of the inventors needed mathematics principles to formulate solutions.

Answers

Answer:

All of the inventors can be characterized as problem-solvers.

Explanation:

Took the practice

Answer:

All of the inventors can be characterized as problem-solvers.

Explanation:

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