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
MAVERICK [17]
3 years ago
7

A student wearing frictionless in-line skates on a horizontal surface is pushed, starting from rest, by a friend with a constant

force of 60 N. How far must the student be pushed, so that her final kinetic energy is 300J?
Physics
2 answers:
grin007 [14]3 years ago
8 0

Answer:

Physics

Explanation:

Explanation:

We can use the Theorem of Work (W) and Kinetic Energy (K):

W=ΔK=Kf−Ki

it basically tells us that the work done on our system will show up as change in Kinetic Energy:

We know that the initial Kinetic Energy, Ki=12mv2i, is zero (starting from rest) while the final will be equal to 352J; Work will be force time displacement. so we get:

F⋅d=Ff

45d=352

and so:

d=35245=7.8≈8m

galben [10]3 years ago
3 0

Answer:

d= 352/45=7.8≈ 8m

Explanation

We can use the Theorem of Work (W) and Kinetic Energy (K):

W=ΔK=k <em>f</em> - k <em>i </em>, it is basically tells us that the work done on our system will show up as change in Kinetic Energy:We know that the initial Kinetic Energy, k<em>i</em> =1/2 <em>mv</em> 2/i, is zero (starting from rest) while the final will be equal to 352J; Work will be force time displacement. so we get: F . d = F<em>f</em>

45<em>d</em>= 352 and so d= 352/45=7.8 ≈ <em>8m</em>

You might be interested in
In a house, 3 bulbs of 60 watt each are lighted for 3 hours daily, 4 fans of 100 watt each are used for 8 hours daily and an ele
Virty [35]

Answer:

Total Energy consumed = 146.94 kwh

Total cost = rs 587.76

Explanation:

Given:

3 bulbs each 60 watt [for 3 hours daily]

4 fans each 100 watt [for 8 hours daily

1 electric heater of 2 kWh (2,000 watt) [for half hour daily ]

Rate = rs 4/Kwh

Find:

Total Energy consumed

Total cost

Computation:

Energy used = Power × time

3 bulbs each 60 watt [for 3 hours daily]  = 3 x 60 x 3 x 31 = 16,740 watt = 16.74 kw

4 fans each 100 watt [for 8 hours daily  = 4 x 100 x 8 x 31 = 99,200 watt = 99.2 kw

1 electric heater of 2 kWh [for half hour daily ] = 1 x 2000 x (1/2) x 31 = 31,000 watt = 31 kw

Total Energy consumed = 16.74 + 99.2 + 31

Total Energy consumed = 146.94 kwh

Total cost = 146.94 x 4

Total cost = rs 587.76

5 0
3 years ago
A plumber is trying to fix a clog in a vertical pipe, but does not know how far down in the pipe the clog and the water level is
PIT_PIT [208]

Answer:

the shortest distance to the obstruction is 0.431 m

Explanation:

We can see this system as an air column, where the plumber is open and where the water is closed, in the case when he hears the sound there is a phenomenon of resonance and superposition of waves with constructive interference.

For the lowest resonance we must have a node where the water is and a maximum where the plumber is a quarter of the wavelength

       λ = ¼ L

If we are in a major resonance specifically the following resonance. We have a full wavelength plus a quarter of the wavelength

    λ = 4L / 3

The general formula is

    λ = 4L / n            n = 1, 3, 5, 7,…

In addition the wave speed is the product of the frequency by the wavelength

    v = λ f

Let's replace

    v = (4L / n) f

    L = v n / (4 f)

Now we can calculate the depth or length of the air column

If we have the first standing wave n = 1

    L = 340 1 / (4 197)

    L = 0.431 m

If it is the second resonance n = 3

    L = 340 3 / (4 197)

    L = 1.29 m

We can see the shortest distance to the obstruction is 0.431 m

5 0
3 years ago
PRELIMINARY QUESTIONS
zimovet [89]
French fries were on your car
3 0
3 years ago
What does the slope on a velocity-time graph measure?
Lostsunrise [7]

Answer:The slope in the velocity-time graph represents the acceleration. The slope is defined as the ratio of change in y-axis to change in the x-axis. The slope is represented by the letter m and following is the general formula used for determining the slope:

Explanation:

6 0
3 years ago
Read 2 more answers
How does quantum theory explain the emission spectra of atoms?
ankoles [38]
The correct answer is B.

Let us think of the classical theory first. In the classical theory, light is a wave that gives energy. This energy gradually helps the electron jump to a higher energy level.
In quantum theory, this is wrong; an electron cannot absorb a small amout of energy because there is not close enough state to jump to with that energy; only very specific amounts of energy lead to a change in orbital levels/ absorbance of energy. Also, each pair of energy levels has a specific energy difference that is needed from an electron so that it can move.
Hence, B is correct; all other sentences describe classical models of light-electron interactions

4 0
4 years ago
Read 2 more answers
Other questions:
  • A clock clicks 50 times in 12 seconds. Calculate the frequency and period of the clock.
    7·2 answers
  • What is the name of the hottest and brightest supergiant star?
    7·2 answers
  • What is the relashinship between the mass and size of a planet?
    6·1 answer
  • What discovery lead J.J. Thomson to decide that atoms were not indivisible, but are actually composed of smaller parts? Thomson
    12·2 answers
  • Radar, Radio, Microwaves are examples of this kind of energy im so confused on what energy this is
    9·1 answer
  • A person has a gravitational force (weight) of 600 N on Earth. Suppose the mass of the Earth is double and the radius shrinks to
    13·1 answer
  • you place a one-liter substance in a 2-liter bottle and tightly cover the bottle. the substance expands until it completely fill
    13·1 answer
  • Is there gravity in water?
    10·2 answers
  • How does the speed of light change as the index of refraction increases?.
    13·1 answer
  • An example of inertia is when your body flies forward when you slam on the breaks.
    7·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!