1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Umnica [9.8K]
3 years ago
10

Two movers use a rope system to lift a box to a third-story apartment. They do 1,200 J of work on the rope system, and the rope

system does 1,020 J of work on the box. What is the efficiency
Physics
2 answers:
xeze [42]3 years ago
8 0
Efficiency is defined as the measure of the amount of work or energy is conserved in a certain process. At all times, in every process, work or energy is always lost or wasted due to certain interference. Not all work given is converted to useful work or energy. Thus , efficiency is calculated by dividing the energy or work output to the energy or work input then the value is multiplied by 100 to express efficiency as percentage.

Efficiency = work output / work input
Efficiency = (1020 J / 1200 J) = 85%
Kruka [31]3 years ago
3 0

Answer:

85%

Explanation:

You might be interested in
How do you do to your question to see if its answered?
Jobisdone [24]

Answer:

Go in notifications, it'll show if it was answered. If it doesn't show that a person answered it, wait a while, someone might respond :)

Explanation:

On the Top right of your screen, theres a bell button. Click that and it will show all the notifications. it will also show if a person answered it.

It will pop up like

*random username*  answered your question! ]

Hope this helped

6 0
3 years ago
Read 2 more answers
A 0.547 kg pizza is thrown straight up in the air. At a height of 2.30 m above the surface of the earth it has a speed of 5.00 m
natima [27]

Answer:

The total mechanical energy of the pizza crust is 19.2 J.

Explanation:

Mechanical energy is that which a body or a system obtains as a result of the speed of its movement or its specific position, and which is capable of producing mechanical work. Then:

Potential energy + kinetic energy = total mechanical energy

Kinetic energy is a form of energy. It is defined as the energy associated with bodies that are in motion and this energy depends on the mass and speed of the body.

Kinetic energy is defined as the amount of work necessary to accelerate a body of a certain mass and in a position of rest, until it reaches a certain speed.

Kinetic energy is represented by the following formula:

Ec = ½ *m*v²

Where Ec is kinetic energy, which is measured in Joules (J), m is mass measured in kilograms (kg), and v is velocity measured in meters over seconds (m / s).

In this case:

  • m=0.547 kg
  • v= 5 m/s

Replacing:

Ec = ½ *0.547 kg*(5 m/s)²

and solving you get:

Ec= 6.8375 J

On the other hand, potential energy is the energy that measures the ability of a system to perform work based on its position. In other words, this is the energy that a body has at a certain height above the ground.

Gravitational potential energy is the energy associated with the gravitational force. This will depend on the relative height of an object to some reference point, the mass, and the force of gravity. Then for an object with mass m, at height h, the expression applied to the gravitational energy of the object is:

Ep = m*g*h

Where Ep is the potential energy in joules (J), m is the mass in kilograms (kg) is h the height in meters (m) and g is the acceleration of fall in m / s² (approximately 9.81 m/s²)

In this case:

  • m= 0.547 kg
  • g= 9.81 m/s²
  • h= 2.30 m

Replacing

Ep= 0.547 kg *9.81 m/s²* 2.30 m

and solving you get:

Ep= 12.342 J

So:

Total mechanical energy= 12.342 J + 6.8375 J

Total mechanical energy= 19.1795 J≅ 19.2 J

<u><em>The total mechanical energy of the pizza crust is 19.2 J.</em></u>

6 0
3 years ago
Can you respond this two questions, please? :
Andrews [41]

Where's the diagram for question 1?

6 0
3 years ago
A clamp-type measuring instrument operates on the principle of
Hitman42 [59]

<em>A clamp-type measuring instrument operates on the principle of; </em>

A. induction

8 0
3 years ago
Define unit aland how many types of unit are there . Name them?​
Lana71 [14]

Answer:

7. They arethe meter (m), the kilogram (kg), the second (s), the kelvin (K), the ampere (A), the mole (mol), and the candela (cd)

Explanation:

7. They arethe meter (m), the kilogram (kg), the second (s), the kelvin (K), the ampere (A), the mole (mol), and the candela (cd)

4 0
2 years ago
Other questions:
  • Quick! how did Daniel hale Williams contribute to science?
    10·1 answer
  • If a radio wave has a period of 1 μs what is the wave's period in seconds
    14·1 answer
  • What structure is located at the front edge of the retina and has a tooth like appearance?
    15·1 answer
  • A 92-kg fullback moving south with a speed of 5.8 m/s is tackled by a 110-kg lineman running west with a speed of 3.6 m/s. Assum
    11·1 answer
  • A standard for comparison that helps to ensure that the experimental result is caused by the condition being tested is the ____.
    6·1 answer
  • Consider the air moving over the top of the light bulb. The streamlines near the bulb will be squeezed together as the air goes
    10·1 answer
  • A hair dryer draws 11 A when it is connected to 120 V. If electrical energy costs $ 0.09/kW·h, what is the cost of using the hai
    7·1 answer
  • Donuts are a simple or complex carbohydrate? *<br> Ok
    5·1 answer
  • Im so nervous about something and I need advice!!! PPPLLLLZZZZ DO NOT REPORT!! WILL MARK BRAINLIEST!!!
    7·1 answer
  • Joaquin is at rest at the top of a hill on a skateboard. Four seconds later, he reaches the bottom of the hill at a final veloci
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!