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
nlexa [21]
3 years ago
9

A string is being pulled with a force of 20 N and moves a 5 kg block to the left at a constant speed. What is the coefficient of

friction for between the floor and the block? Enter your answer as a decimal value (Example: 0.72) * I think the answer is 20 but this question is starting frustrating me
Physics
1 answer:
Valentin [98]3 years ago
6 0

Answer:

μ = 0.4

Explanation:

As, the object is moving at a constant speed. Therefore, the unbalanced force on it must be equal to zero. So, the frictional force on the object must be equal to the force applied to it:

F = frictional force

F = μR = μW = μmg

where,

F = Applied Force  = 20 N

μ = coefficient of friction between wall and floor = ?

m = mass of block = 5 kg

g = 9.8 m/s²

Therefore,

20 N = μ(5 kg)(9.8 m/s²)

μ = 20 N/49 N

<u>μ = 0.4</u>

You might be interested in
There are 5510 lines per centimeter in a grating that is used with light whose wavelegth is 467 nm. A flat observation screen is
Mademuasel [1]

Answer:

1.696 nm

Explanation:

For a diffraction grating, dsinθ = mλ where d = number of lines per metre of grating = 5510 lines per cm = 551000 lines per metre and λ = wavelength of light = 467 nm = 467 × 10⁻⁹ m. For a principal maximum, m = 1. So,

dsinθ = mλ = (1)λ = λ

dsinθ = λ

sinθ = λ/d.

Also tanθ = w/D where w = distance of center of screen to principal maximum and D = distance of grating to screen = 1.03 m

From trig ratios 1 + cot²θ = cosec²θ

1 + (1/tan²θ) = 1/(sin²θ)

substituting the values of sinθ and tanθ we have

1 + (D/w)² = (d/λ)²

(D/w)² = (d/λ)² - 1

(w/D)² = 1/[(d/λ)² - 1]

(w/D) = 1/√[(d/λ)² - 1]

w = D/√[(d/λ)² - 1] = 1.03 m/√[(551000/467 × 10⁻⁹ )² - 1] = 1.03 m/√[(1179.87 × 10⁹ )² - 1] = 1.03 m/1179.87 × 10⁹  = 0.000848 × 10⁻⁹ = 0.848 × 10⁻¹² m = 0.848 nm.

w is also the distance from the center to the other principal maximum on the other side.

So for both principal maxima to be on the screen, its minimum width must be 2w = 2 × 0.848 nm = 1.696 nm

So, the minimum width of the screen must be 1.696 nm

4 0
3 years ago
A hydraulic lift has pistons with diameter 28cm and 70cm, respectively. If a force of 500 N is exerted at the input piston. What
Crazy boy [7]

Answer:

3125 N

Explanation:

diameter /2 =radius

so r1 =14cm , r2 =35cm

f1/A1 =f2/A2.

f2 = f1 × A2 / A1

=500×1225 pi cm² / 96 pi cm²

f2 =3125N

4 0
3 years ago
When an electron moves 2.5 m in the direction of an electric field, the change in electrical potential energy of the electron is
anygoal [31]
In the field of electromagnetism, when two charged plates that are situated opposite to each other by a certain distance, it forms an energy called the electric field. This energy is due to the difference in potential energy with respect to distance. Thus,

E = V/d

However, the voltage in volts is energy per coulomb. Thus,
V = (8x10-17 J/electron)*(1electron/1.60218x10^-19 C)
V = 499.32 volts

Therefore,

E = 499.32 volts /2.5 m
E = 199.73 N/C

The electric field that caused the change in potential energy is equal to 199.73 Newtons per Coulomb.
7 0
3 years ago
How many kindergarteners do you think you can take on a fight before getting tired or over powered?
yulyashka [42]
Is this a serious question ?
4 0
3 years ago
Read 2 more answers
Please, I need help with this.
solmaris [256]

this is the answer :)

6 0
3 years ago
Read 2 more answers
Other questions:
  • A uniform cubical crate is 0.740 m on each side and weighs 600 N. It rests on the floor with one edge against a very small, fixe
    9·1 answer
  • wo kids are on a seesaw. The one on the left has a mass of 75 kg and is sitting 1.5 m from the pivot point. The one on the right
    9·1 answer
  • The difference in energy () between vibrational energy levels is determined by the nature of the bond. If a photon of light poss
    15·1 answer
  • As a bat flies toward a wall at a speed of 6.0 m/s, the bat emits an ultrasonic sound wave with frequency 30.0 kHz. What frequen
    13·1 answer
  • A solar-powered car is traveling at constant speed around a circular track. what happens to the centripetal acceleration of the
    7·1 answer
  • A fish swimming in a horizontal plane has velocity i = (4.00 + 1.00 ) m/s at a point in the ocean where the position relative to
    12·1 answer
  • Will ice melt faster in salt, sugar or water?
    5·1 answer
  • What is the change in internal energy if 70 J of heat is added to a system and
    8·1 answer
  • How many cups are in 4 gallons
    9·1 answer
  • Two particles of a gas collide. Why is this considered an elastic collision? (1 point)
    13·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!