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

Help
Why do you think that if you drop two balls, exactly two balls rise on the other side at a
similar speed?

Answers

Answer:

It conserves both energy and momentum in the collision at the same time. By design, when the balls collide the strings that hold them up are vertical (assuming balls are only swung from one side).

Explanation:

Hope This Helps!!

A student pushes a 50-N box across the floor a distance of 15 m. How much work was done to move the box?
1) 750 j
2) 75 J
3) no work was done
4) 7500 J

Answers

Answer:750

Explanation:

50 times 15

Answer:

750 j

Explanation:

I took the test in k12

How much time does it take for a spinning baseball with an angular speed of 38 rad/s to rotate through 15 degrees

Answers

Answer:

the time of motion of the ball is 6.89 ms.

Explanation:

Given;

angular speed, ω = 38 rad/s

angular distance, θ = 15 degrees

Angular distance in radian;

[tex]\theta = 15^0 \times\frac{2\pi \ rad}{360^0} = 0.2618 \ rad[/tex]

Time of motion is calculated as;

[tex]time = \frac{angular \ distance}{angular \ speed} \\\\t= \frac{\theta}{\omega} = \frac{0.2618 \ rad}{38 \ rad/s} \\\\t = 6.89 \ \times 10^{-3} \ s\\\\t = 6.89 \ ms[/tex]

Therefore, the time of motion of the ball is 6.89 ms.

Am needing help with this!!! Please hell

Answers

Answer:

ology

Explanation:

In a good hit, a baseball and bat are in contact with each other for about 1 millisecond. In the first game of the 2012 World Series, Tigers pitcher Justin Verlander threw a 100-mph pitch to the Giants' Pablo Sandoval. Sandoval's hit returned the ball directly back at Verlander at 70 mph. Calculate the average force of the bat on the ball, during the contact. Round the final answer to the nearest whole number.

Answers

Answer:

Explanation:

100 mph = 100 x 1760 x 3 / ( 60 x 60 )

= 146.67 ft / s

70 mph = 70 x 1760 x 3 / ( 60 x 60 )

= 102.67 ft/s

Let mass of the ball = m .

The ball which was moving with a velocity of 146.67 ft/s is turned back by the action of force of bat on the ball and it moved in opposite direction with velocity of - 102.67 ft/s ( - ve sign due to reversed direction )

If m be the mass of ball

change in momentum = m x 146.67 - ( - m x 102.67 )

=  m x 146.67 +  m x 102.67

= 249.34 m

Change in momentum = impulse = force x time

Putting the given values

249.34 m = force x 1 x 10⁻³ ( time = 10⁻³ s )

force = 249.34 m x 10³ poundal .

Here m is mass of the ball in lb .

Substances which naturally attract each other called what

Answers

Answer:

Ferromagnetism, physical phenomenon in which certain electrically uncharged materials strongly attract others. Two materials found in nature, lodestone (or magnetite, an oxide of iron, Fe3O4) and iron, have the ability to acquire such attractive powers, and they are often called natural ferromagnets.

Hope this help :)

an object has a mass of 4kg and an average acceleration of 10m/s/s what is the force​

Answers

Force = mass x acceleration
Force = 4kg x 10m/s^2
Force = 40N

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

Gravitational potential energy is due to....
a. mass and height above the ground
b. the amount of power an object has
c. the speed of an object
d. how far an object is stretched

Answers

Answer:

A

Explanation:

I only think its A because of the gravity part...sorry im not good at explaining

I'll mark brainiest if you help me

Answers

question 4 is true, question 5 is B.

A passive continental margin has a ____, while an active margin does not.
O A. continental rise
O B. continental slope
O C. continental duct
O D. continental shelf​

Answers

A I think
I’m gonna go with A but I might be wrong

A passive continental margin has a continental rise, while an active margin does not. Therefore, option A is correct.

What is passive continental margin?

Where there is no plate border to mark the transition from land to sea, this is known as a passive continental margin.

A good example is the east coast of the United States, where the plate boundary is a distance from the shore along the mid-Atlantic ridge. Little geological activity occurs along passive borders.

Volcanoes, mountain belts, and earthquakes all identify active margins. They lack a continental uplift and an abyssal plain, in contrast to passive margins.

The Pacific and North American Plate boundaries are visible along the west coast of the United States, which is an example of an active margin. Where there is no plate border to mark the transition from land to sea, this is known as a passive continental margin.

Thus, option A is correct.

To learn more about the passive continental margin, follow the link:

https://brainly.com/question/11505884

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Calculate the energy used by a 0.011 kW lightbulb in 1 minute. Use the formula: energy (J) = power (W) × time (s)

Answers

Answer:

660

Explanation:

0.011kW = 11W

energy = 11 x 60

            = 660J

The baser would be 660 do u need steps

(Physical Science) What is the wavelength of light waves if their frequency is 5.0 x 10^14 Hz and the speed of light is 3 x 10^8 m/s?

Answers

Explanation:

Wavelength = speed of light/frequency

Answer is

[tex]6 \times {10}^{ - 7} [/tex]

Kelly Clarkson is running between the Patronas towers in Kuala Lumpur on a tightrope at a speed of 15 m/s. Kelly currently weighs 79 kg. What is her KE?

Answers

KE = 8887.5 J

Further explanation

Given

speed = 15 m/s

weight = 79 kg

Required

KE-Kinetic energy

Solution

Energy is the ability to do work  

Energy because its motion is expressed as Kinetic energy (KE) which can be formulated as:  

[tex]\large {\boxed {\bold {KE = \frac {1} {2} mv ^ 2}}}[/tex]

Input the value :

KE = 1/2 x 79 kg x 15² m/s²

KE = 8887.5 J

Answer:

KE = 8887.5 J

if you stung by a honey bee. why we suggest rub with baking soda why?​

Answers

Answer:

When a bee stings, it injects methanoic acid into the skin which causes immense pain and irritation. Rubbing of baking soda on the sting area gives relief because, being alkaline in nature, baking soda neutralizes the effect of methanoic acid and gives relief.

Cause we believe as humans that r

Insert the values
A train is traveling at a speed of 100km/hr for 3 hours. It then speeds up to 2 poin
150km/hr for the next 2 hours. How far has the train gone at the end of 5hours

Answers

Answer:

300km

Explanation:

To find the total distance traveled within the given time frame, we need to known that distance is the product speed and time;

  Distance  = Speed x time

For the first lap:

   Distance  = 100km/hr x 3hr = 300km

 

For the second lap;

     Distance  = 150km/hr x 2  = 300km

Distance  = 300km + 300km

So;

Distance = 300km

A student is given a sample of matter and asked to determine whether it is an element.

Answers

I think the correct answer is C
it's a mixture cause the 3 different pure substances can only be separated if its a mixture

Astronomers classify galaxies by their shape. Which of the following terms describes a galaxy that looks like a round or flattened ball and contains little gas and dust between the stars?
A.
elliptical galaxy
B.
irregular galaxy
C.
No galaxies are shaped like a ball
D.
spiral galaxy

Answers

A. Elliptical galaxy

12. In which of the positions shown in the picture, will Joshua have both potential and kinetic energy?​

Answers

Answer:

Answer: D. Only R

Explanation:

The Principle Of Conservation Of Mechanical Energy

In the absence of friction, the total mechanical energy is conserved. That means that

Em=U+K is constant, being U the potential energy and K the kinetic energy.

At the top of the path (point Q), Joshua is at rest but his height is at a maximum. Thus his kinetic energy is zero.

At point P, Joshua is at the minimum level (potential energy zero) and his speed is at a maximum.

At point R, Joshua has some height and some speed which means he has both types of energy.

Answer: D. Only R

Which tissue lines the upper respiratory tract, secretes, and movement of mucus by ciliary
action.

Answers

Answer:

The respiratory system is lined with a mucous membrane that secretes mucus. The mucus traps smaller particles like pollen or smoke. Hairlike structures called cilia line the mucous membrane and move the particles trapped in the mucus out of the nose.

Explanation:

A circuit with a 10 V battery and two 3 resistors in series. what is the current through the circuit.

Answers

Answer:

please use the formula to find the current/use ohms law

Explanation:

I=v/r

Help in physics please. Need asap :(((​

Answers

Answer:

which class you are studying hear the everything is based on the tangent line I didn't even handle this I am sorry

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:

Which statement best describes the atoms of elements that form compounds by covalent bonding?
They share electrons between them.
They have a large difference in valence electron number
They have a large difference in atomic mass.
They are in the same period in the periodic table.

Answers

Answer:

they share electrons between them.

Explanation:

taking the test rn lol i think its right

Which metric prefix has a decimal form of 0.01?​

Answers

Answer:

Centi is the metric prefix for 0.01

Which of the following is an example of an electromagnet?
A. The magnets used to lift metal or cars in a salvage/junk yard
B. the bar magnets we used in the lab
C.the magnets used to hold pictures on a refrigerator or papers on a metal filing cabinet

Answers

Answer:

A. The magnets used to lift metal or cars in a salvage/junk yard

Explanation:

An electromagnet  is defined as a type of magnet which are made up of wires in coil shape. Magnetic field in these wires are produced by electric current.

An example of an electromagnet is magnets used to lift metal or cars in a salvage/junk yard because a crane is used in junkyard to lift metal in which crane is attached to a iron disc and when electricity is off, the disc move downwards and placed near required metal and switch on the electricity when disc reaches on metal or cars to be lifted. This electricity generates magnetism in the iron disc and attract metal or cars from the junkyard.

Hence, the correct answer is "A. The magnets used to lift metal or cars in a salvage/junk yard".

HELPPPPPP this due in 10 mins

Answers

Answer:

I dont really know but i think its water type of energy

Explanation:

Hope it helps

The type of energy that takes place in the model is Electrical Energy

¿Qué trabajo realiza una carreta que contiene una de masa 800 lb de cemento si se desplaza 100 m por un suelo nivelado?

Answers

Answer:

Ver respuesta en el procedimiento

Explanation:

En este caso, necesitamos la expresión que nos permite hallar el Trabajo realizado por un objeto a través de una distancia dada. Esa expresión es:

W = F * x   (1)

Donde:

W: Trabajo en Joules (J)

F: Fuerza en Newton (N)

x: Distancia o radio en metros (m)

En este caso, solo tenemos una masa de 800 lb, y la distancia que se esta recorriendo. No tenemos ningún dato adicional que nos diga si por ejemplo, es empujado por una persona o parecido, solo los datos de la masa que lleva la carreta. Por lo tanto, la única fuerza que podemos asumir se está ejerciendo, sería la fuerza del peso del objeto que se calcula así:

P = mg   (2)

Donde:

g: aceleración de gravedad (9,8 m/s²)

Ahora bien si reemplazamos (2) en (1) nos queda:

W = mgx  (3)

Y antes de realizar el cálculo debemos convertir la unidad de masa en libra a kilogramo, usando la siguiente conversión:  1 lb -----> 0,454 kg por tanto:

m = 800 * 0,454 = 363.2 kg

Ahora podemos usar (3) y calcular el trabajo:

W = 363,2 * 9,8 * 100

W = 355936 J o simplemente 355,936 kJ

Espero te sirva.

PD: También puedes usar el valor de gravedad como 10 m/s² y tendrás un resultado de 363200 J o 363,2 kJ.

WILL GIVE BRAINLIEST!!! Over and over, the cycle of rock sinking and rising takes place due to convection currents in Earth. One full cycle takes millions of years. What forces drive the convection currents that cause this cycle to take place?
Group of answer choices

heating from the crust and mantle

heating from the core and mantle

cooling from the crust and core

cooling from the core and mantle

Answers

Answer: Heating from the crust and mantle.

Explanation: Tremendous heat and pressure within the earth cause the hot magma to flow in convection currents. These currents cause the movement of the tectonic plates that make up the earth's crust.

The convection currents that cause this cycle to take place is driven by heating from the crust and mantle. Hence, option (a) is correct option.

What is rock cycle?

A crucial idea that illustrates the changes between the three primary rock types is the "rock cycle" (metamorphic, igneous and sedimentary). Simply put, it is a series of processes that create and modify the various types of rocks found in the Earth's crust.

The solid crust of Earth serves as a heat insulator for the planet's warm interior. The molten rock in the mantle, below the crust, is known as magma. Convection currents are created by the intense heat and pressure that exists within the earth. The tectonic plates that make up the earth's crust shift as a result of these currents.

Learn more about rock cycle here:

https://brainly.com/question/29767269

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If two forces are acting on an object , one is 25N west, and the other is 50N east. Calculate the net force.

Answers

Answer:

Explanation:

Since the forces are only in the x-direction, you could just add the two forces. The West is to the left, so it would be -25N with the negative sign indicating direction. The East is to the right, so that would be +50N.

50 + (-25) = 25N to the right or the positive i-hat direction

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