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
jasenka [17]
3 years ago
6

A 63.0-kg man is riding an escalator in a shopping mall. The escalator moves the man at a constant velocity from ground level to

the floor above, a vertical height of 4.20 m. What is the work done on the man by (a) the gravitational force and (b) the escalator
Physics
1 answer:
Oliga [24]3 years ago
8 0

Answer:

Explanation:

Given that,

Mass of man =Mm=63kg

W=mg

W=63×9.81

W=618.03N

g=9.81m/s²

The escalator moves at a constant velocity, then this shows that it is not accelerating, then, a=0m/s²

Height escalator traveled

H=4.2m.

We assume that the weight of the escalator is negligible.

a. Work done by gravity

Work done by gravity is given as

Work done(gravity)=mgh

Since the work is done against gravity, then, g is negative

Then,

Work done(gravity)=-mgh

Work done(gravity)=-63×9.81×4.2

Work done(gravity)=-2595.726J

b. Work done by escalator

Using equation of motion to know the force pulling the escalator upward

ΣF = ma, but a=0

ΣF = 0

Only two force is acting on the in y axis, the Normal force and the weight

N-W=0

N=W

Since W=618.03N

Then, N=618.03

The normal is the force pulling the escalator upward

Then, the work done by escalator is given as

Work done=Force × distance

Work done=618.03×4.2

Work done= 2595.76J

Work done by escalator is 2595.76J

You might be interested in
The frequency and wavelength of EM waves can vary over a wide range of values. Scientists refer to the full range of frequencies
zloy xaker [14]

Answer:

b.) All these technologies use radio waves, including high-frequency microwaves

d.) Microwave ovens emit in the same frequency band as some wireless Internet devices.

e.) The radiation emitted by wireless Internet devices has the shortest wavelength of all the technologies listed above.

f.) All these technologies emit waves with a wavelength in the range of 0.10 to 10.0 m.

Explanation:

For option D. The frequency range of microwave ovens is 2450 MHz = 2.4 GHz, which intersects with wireless internet technology with range of 2.4 to 2.6 GHz.

For E, wavelenght and frequency are inversely proportional. Wireless internet service has the greatest frequency band and hence the shortest wavelenght band.

For F, in all these radiations, the highest Freq is 2.6 GHz and the lowest is 40 MHz. Wavelenght is speed of light (3x10^8 m/s) divided by the frequency.

2.6 GHz = 2.6x10^9 Hz

Wavelenght = 3x10^8 ÷ 2.6x10^9 = 0.1 m

40 MHz = 40x10^6

Wavelenght = 3x10^8 ÷ 40x10^6 = 7.5 m

4 0
3 years ago
What is the relationship between radio waves and the visible spectrum
evablogger [386]

Answer:

They both are part of electromagnetic radiation.

Radio waves have longer wavelength than visible waves.

Radio waves have lower frequency than visible waves.

Explanation:

8 0
3 years ago
Describe succinctly the relationship between how far a galaxy is from us (its distance), versus how fast it is moving.
Eva8 [605]

Answer:

Distance is directly proportional to the velocity

Explanation:

In 1929, Edwin Hubble's wrote an article that talked about relationship between the distance and recession speed/velocity of galaxies which led to what is known as the Hubble Law. This law states that galaxies are moving away from the earth at velocities proportional to their distances.

Thus is written as;

v = H_o•d

Where;

v is velocity

d is distance

H_o is Hubble's constant rate of cosmic expansion.

He came to this conclusion by generating a graph known as Hubble's classic graph which was a graph of observed velocity vs distance for nearby galaxies.

7 0
3 years ago
Hello people ~
o-na [289]

Answer:

<u>(B) wheat</u>

Explanation:

  • Wheat is an <u>anemophilous</u> plant (form of pollination by which wind distributes pollen)
  • They lack petals and sepals (outer whorls of the flower)
  • The female plants consist of an ovary (female reproductive part) from which two styles (connecting stigma and ovary) arise
  • The feathery stigma catches the pollen and sends it to the ovary for fertilization
6 0
2 years ago
Read 2 more answers
80 grams of iron at 100°C is dropped into 200 of water at 20°C contained in an iron vessel of mass 50 gram find the resulting te
vodka [1.7K]

Answer:

the resulting temperature is 23.37 ⁰C

Explanation:

Given;

mass of the iron, m₁ = 80 g = 0.08 kg

mass of the water, m₂ = 200 g = 0.2 kg

mass of the iron vessel, m₃ = 50 g = 0.05 kg

initial temperature of the iron, t₁ = 100 ⁰C

initial temperature of the water, t₂ = 20 ⁰C

specific heat capacity of iron, c₁ = 462 J/kg⁰C

specific heat capacity of water, c₂ = 4,200 J/kg⁰C

let the temperature of the resulting mixture = T

Apply the principle of conservation of energy;

heat lost by the hot iron = heat gained by the water

m_1c_1 \Delta t_1 = m_2c_2\Delta t_2\\\\m_1c_1 (100 - T) = m_2c_2 (T- 20)\\\\0.08 \times 462 (100-T) = 0.2 \times 4,200 (T-20)\\\\36.96 (100-T) = 840 (T-20) \\\\100 - T = 22.72 (T-20)\\\\100-T = 22.72 T - 454.4 \\\\554.4 = 23.72T\\\\T = \frac{554.4}{23.72} \\\\T = 23.37 \ ^0C

Therefore, the resulting temperature is 23.37 ⁰C

6 0
3 years ago
Other questions:
  • A vehicle traveling at a steady speed takes 4 hours to travel 244 km. calculate the average speed of this vehicle.
    8·1 answer
  • The Chevy Corvette Z06 is claimed to accelerate from a standing start to 60 miles per hour in 3 seconds. Estimate its accelerati
    8·1 answer
  • Which is not an example of how an object gains elastic potential energy by stretching?
    11·1 answer
  • Which of the following would not make a good insulator
    13·1 answer
  • What is the last step in creating an argumentative essay?
    6·1 answer
  • "For punishment to work (i.e., to weaken the frequency of undesirable behaviors without creating a backlash), the punishment mus
    15·1 answer
  • All enzymes are examples of organic molecules<br> known as?
    13·1 answer
  • Que fracción de luz que llega directa a una lamina de vidrio se refleja en la primera superficie?
    6·1 answer
  • Se lanza hacia arriba un objeto con una velocidad de 72 Dam/min y al mismo tiempo se deja caer una pelota desde una altura de 32
    10·2 answers
  • The critical path is the sequence of activities that determine the latest date by which the project can be evaluated.
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!