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
scoray [572]
3 years ago
10

A box of mass 60 kg is at rest on a horizontal floor that has a static coefficient of friction of 0.6 and a kinetic coefficient

of 0.25
a)The minimum force necessary to start moving the box
b) The friction force and the acceleration of the box if a horizontal force of 400 N is applied
Physics
1 answer:
melisa1 [442]3 years ago
4 0

Answer:

a) F = 353.2 N

b) F_{f} = 147.2 N

   a = 4.21 m/s²

Explanation:

a) The minimum force necessary to start moving the box s given by:       

\Sigma F = 0

F - \mu_{s}N = 0

F = \mu_{s}mg

Where:

F: is the force applied to move the box

μs: is the static coefficient of friction = 0.6          

m: is the mass = 60 kg

g: is the gravity = 9.81 m/s²

F = 0.6*60 kg*9.81 m/s^{2} = 353.2 N

b) The acceleration is:

F - F_{f} = ma

F - \mu_{k}mg = ma              

a = \frac{F - \mu_{k}mg}{m} = \frac{400 N - 0.25*60 kg*9.81 m/s^{2}}{60 kg} = 4.21 m/s^{2}

Now, the friction force is:

F_{f} = \mu_{k}mg = 0.25*60 kg*9.81 m/s^{2} = 147.2 N

I hope it helps you!    

You might be interested in
A small logo is embedded in a thick block of crown glass (n = 1.52), 4.70 cm beneath the top surface of the glass. The block is
harkovskaia [24]

The concept required to solve this problem is the optical relationship that exists between the apparent depth and actual or actual depth. This is mathematically expressed under the equations.

d'w = d_w (\frac{n_{air}}{n_w})+d_g (\frac{n_{air}}{n_g})

Where,

d_g = Depth of glass

n_w = Refraction index of water

n_g = Refraction index of glass

n_{air} = Refraction index of air

d_w = Depth of water

I enclose a diagram for a better understanding of the problem, in this way we can determine that the apparent depth in the water of the logo would be subject to

d'w = d_w (\frac{n_{air}}{n_w})+d_g (\frac{n_{air}}{n_g})

d'w = (1.7cm) (\frac{1}{1.33})+(4.2cm)(\frac{1}{1.52})

d'w = 4.041cm

Therefore the distance below the upper surface of the water that appears to be the logo is 4.041cm

3 0
3 years ago
What was the result of the Mexican army's victory over the Texan garrison at the Alamo?
sasho [114]

The result of the Mexican victory was that fallen defenders became heroes to the cause of Texan independence.<span> The Battle of the Alamo took place between February 23 and March 6, 1836 and became the central episode of the Texas Revolution . After this thirteen-day battle, the Mexican troops of General President Antonio Lopez de Santa Anna began an attack on San Antonio de Bexar, the current San Antonio in Texas. The Battle of the Alamo fought the army of Mexico against a group of Texan rebels, mostly American settlers. More than four thousand men from Santa Ana stood in front of the Alamo Fort , the last stronghold of the rebels, which barely reached 187. The Alamo was not a fortress prepared to withstand a siege. It is believed that all the rebels of the Alamo died in the siege, but Santa Anna came to lose up to about 900 men during the days that lasted the fight. However, the worst result for Santa Ana was precisely the resistance that the Texan rebels had in the Alamo, which fostered the fighting spirit of the Texans. A few days later, on March 14, 1836, Texas became independent from Mexico and a month later, Santa Ana was imprisoned.</span>

3 0
3 years ago
Read 2 more answers
Waves<br> Please need help fast
mixas84 [53]
I believe its the third answer
6 0
2 years ago
Worth 50 point!!!
olasank [31]

Answer:

Chief Hopper

Explanation:

Mike travels at a constant speed of 3.1 m/s.  To find how long it takes him to reach the school, we need to find the distance he travels.  We can do this using Pythagorean theorem.

a² + b² = c²

(1000 m)² + (900 m)² = c²

c ≈ 1345 m

So the time is:

v = d / t

3.1 m/s = 1345 m / t

t ≈ 434 s

Next, Chief Hopper travels a total distance of 1900 m, starting at rest and accelerating at 0.028 m/s².  So we can use constant acceleration equation to find the time.

d = v₀ t + ½ at²

1900 m = (0 m/s) t + ½ (0.028 m/s²) t²

t ≈ 368 s

So Chief Hopper reaches the school first, approximately 66 seconds before Mike does.

3 0
3 years ago
A fast pitch softball player does a "windmill" pitch moving her hand through a vertical circular arc to pitch a ball at 70mph. T
uysha [10]

Answer:

Explanation:

The hand throwing ball moves on a circular path having radius r = .55 m

mass of ball m = .19 kg

velocity v = 70 mph

= 70 x 1600 / 60 x 60

= 31.11 m /s

centripetal force

= mv² / r

= .19 x 31.11² / .55

= 334.34 N

8 0
3 years ago
Other questions:
  • Which substance is used to remove rust from metal?
    11·2 answers
  • A protostar forms once the nebular cloud condenses and the core begins
    14·2 answers
  • Create a piece of evidence showing the relationship between potential and kinetic energy You MUST include the following words: p
    7·1 answer
  • O How are electricity and magnetism related?
    5·1 answer
  • Use differentials to estimate the amount of tin in a closed tin can with diameter 3 inch and height 4 inch, if the top and botto
    15·1 answer
  • In the sum of 54.34 and 45.66, the number of significant figure for the<br>answer is​
    5·1 answer
  • In the diagram, q1 = -3.33*10^-9 C and
    9·1 answer
  • 15 points Plz help me no links
    11·2 answers
  • About how much of Earth's water is available for humans to use?
    14·1 answer
  • Ang larong syato ay isang uri ng larong target games​
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!