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
tamaranim1 [39]
3 years ago
11

You want to move a 4- kg bookcase to a different place in the living room. If u push with a force of 65 n and the bookcase accel

erates at 0.12 m/s2 what is the coefficient of kinetic friction between the bookcase and the carpet
Physics
1 answer:
IrinaK [193]3 years ago
7 0

Answer:

1.65

Explanation:

The equation of the forces along the horizontal direction is:

F-F_f = ma (1)

where

F = 65 N is the force applied with the push

F_f is the frictional force

m = 4 kg is the mass

a=0.12 m/s^2 is the acceleration

The force of friction can be written as F_f = \mu R (2), where

\mu is the coefficient of kinetic friction

R is the normal force exerted by the floor

The equation of forces along the vertical direction is

R-mg=0 (3)

since the bookcase is in equilibrium. Substituting (2) and (3) into (1), we find

F-\mu mg = ma

And solving for \mu,

\mu = \frac{F-ma}{mg}=\frac{65-(4)(0.12)}{4(9.8)}=1.65

You might be interested in
A force in the +x -direction with magnitude F(x)=18.0N−(0.530N/m)x is applied to a 7.90 kg box that is sitting on the horizontal
dsp73

Answer:

v\approx 8.570\,\frac{m}{s}

Explanation:

The equation of equlibrium for the box is:

\Sigma F_{x} = 18\,N-(0.530\,\frac{N}{m} )\cdot x = (7.90\,kg)\cdot a

The formula for the acceleration, given in \frac{m}{s^{2}}, is:

a = \frac{18\,N-(0.530\,\frac{N}{m} )\cdot x}{7.90\,kg}

Velocity can be derived from the following definition of acceleration:

a = v\cdot \frac{dv}{dx}

v\, dv = a\, dx

\frac{1}{2}\cdot v^{2} = \int\limits^{17\,m}_{0\,m} {\frac{18\,N-(0.530\,\frac{N}{m} )\cdot x}{7.90\,kg} } \, dx

\frac{1}{2}\cdot v^{2} =\frac{18\,N}{7.90\,kg}  \int\limits^{17\,m}_{0\,m}\, dx  - \frac{0.530\,\frac{N}{m} }{7.90\,kg} \int\limits^{17\,m}_{0\,m} {x} \, dx

\frac{1}{2}\cdot v^{2} = (2.278\,\frac{m}{s^{2}})\cdot x |_{0\,m}^{27\,m}-(0.034\,\frac{1}{s^{2}})\cdot x^{2}|_{0\,m}^{27\,m}

v =\sqrt{2\cdot[(2.278\,\frac{m}{s^{2}})\cdot x |_{0\,m}^{27\,m}-(0.034\,\frac{1}{s^{2}})\cdot x^{2}|_{0\,m}^{27\,m}]  }

The speed after the box has travelled 17 meters is:

v\approx 8.570\,\frac{m}{s}

3 0
3 years ago
What is the acceleration of a car that travels in a straight line?
Sphinxa [80]
Acceleration occurs when there is a change in speed or direction. If it travels in a straight line, there is no speed or change in direction as it is constant througout, hence 0 acceleration.

hope this helps!! ✨
6 0
3 years ago
Read 2 more answers
A civil engineer must design a wheelchair-accessible ramp next to a set of steps leading up to a building. The height from the g
Westkost [7]

Answer:

A) B = 24 ft

B) H = 24.08 ft

C) M.A = 12.04

D) P = 13.7 lb

Explanation:

A)

Minimum allowable length of base of ramp can be found as follows:

Slope = H/B

where,

Slope = 1/12

H = Height of Ramp = 2 ft

B = Length of Base of Ramp = ?

Therefore,

1/12 = 2 ft/B

B = 2 ft * 12

<u>B = 24 ft</u>

B)

The length of the slope of ramp can be found by using pythagora's theorem:

L = √H² + B²

where,

H = Perpendicular = height = 2 ft

B = Base = Length of Base of Ramp = 24 ft

L = Hypotenuse = Length of Slope of Ramp = ?

Therefore,

H = √[(2 ft)² + (24 ft)²]

<u>H = 24.08 ft</u>

D)

The mechanical advantage of an inclined plane is given by the following formula:

M.A = L/H

M.A = 24.08 ft/2 ft

<u>M.A = 12.04</u>

D)

Another general formula for Mechanical Advantage is:

M.A = W/P

where,

W = Ideal Load = 165 lb

P = Ideal Effort Force = ?

Therefore,

12.04 = 165 lb/P

P = 165 lb/12.04

<u>P = 13.7 lb</u>

7 0
3 years ago
An automobile with an initial speed of 4.92 m/s accelerates uniformly at the rate of 3.2 m/s2 . Find the final speed of the car
Rudik [331]

Answer:19.32 m/s

Explanation:

Given

initial speed of car(u)=4.92 m/s

acceleration(a)=3.2 m/s^2

Speed of car after 4.5 s

using equation of motion

v=u+at

v=4.92+3.2\times 4.5=4.92+14.4

v=19.32 m/s

Displacement of the car after 4.5 s

v^2-u^2=2as

19.32^2-4.92^2=2\times 3.2\times s

349.05=2\times 3.2\times s

s=54.54 m

4 0
3 years ago
12. your friend with great excitement tells you about his newest idea to solve the energy crisis: he wants to use an electromoto
mixas84 [53]
I would tell him, in the kindest, most gentle way I could manage,
to fahgeddaboudit. 

The total amount of energy doesn't change.  Energy is never created,
and it never disappears.  If you have some energy, then it had to come
from somewhere, and if you used some energy, then it had to go
somewhere. 

You can never get more energy out of the electromotor than you put into it,
 and in the real world, you can't even get THAT much out, because some
of it is always used on the way through.

Pour yourself a cold glass of soda, then look up "Perpetual Motion" or
"Free Energy" on the internet, relax, and enjoy the show.  They are all
fakes.  They may not all be intentionally meant to fool you, but they are
all impossible.
4 0
3 years ago
Read 2 more answers
Other questions:
  • Running at maximum speed, it takes a boat times as long to go 10 miles upstream as it does to go 10 miles downstream. If the cur
    6·1 answer
  • 2 differences between calorimeter and thermometer ?
    9·1 answer
  • A 0.350kg bead slides on a curved fritionless wire,
    9·1 answer
  • Arrange the phases of the Moon in order of increasing rising time, from the phase with the earliest rising time at 12:00 a.m. to
    6·1 answer
  • Greg is in a bike race. At mile marker four (out of ten), his speed was measured at 13.5 mph.
    13·2 answers
  • How much work is done when holding a 10 N bag of apples while waiting in line at the grocery store for 4 minutes? Group of answe
    10·1 answer
  • Pilots often take advantage of the ____,which are highly-speed winds between 7km and 16 km above earths surface.
    9·1 answer
  • Question 3 of 10
    5·2 answers
  • How much heat does it take to raise a<br> cup of water (2.34 x 10-4 m3) from<br> 15.0 °C to 75.0 °C?
    11·1 answer
  • Can it is possible to complete half syllabus of physics class 11 in 8 days?​
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!