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
kherson [118]
3 years ago
7

The floor of a railroad flatcar is loaded with loose crates having a coefficient of static friction of 0.420 with the floor. If

the train is initially moving at a speed of 57.0 km/h, in how short a distance can the train be stopped at constant acceleration without causing the crates to slide over the floor
Physics
1 answer:
bonufazy [111]3 years ago
7 0

Answer:

The distance is  s=  30.3 \ m

Explanation:

From the question we are told that

   The  coefficient of static friction is  \mu_s  =  0.42

    The  initial speed of the train is  u =  57 \  km /hr = 15.8 \ m/s

   

For the crate not to slide the friction force must be equal to the force acting on the train i.e

       -F_f  =  F

The negative sign shows that the two forces are acting in opposite direction

=>   mg  *  \mu_s  =  ma

=>   -g  *  \mu_s  = a

=>   a =  -9.8 *  0.420

=>   a =  -4.116 m/s^2

From equation of motion

  v^2  = u^2  +  2as

Here  v =  0 m/s since it came to a stop

=>   s=  \frac{v^2 - u^2 }{ 2 a}

 =>   s=  \frac{0 -(15.8)^2 }{ - 2 * 4.116}

=>     s=  30.3 \ m

You might be interested in
Describe the relationship between a moving objects mass and its kinetic energy
WINSTONCH [101]
KE = 1/2 mv^2 is the relationship betwee mass and kinetic energy
8 0
3 years ago
for an ideal monoatomic gas, the internal energy U os due to the kinetic energy and U=3/2RT per mole.show that cv=3/2R per mole
sladkih [1.3K]

Answer:

i. Cv =3R/2

ii. Cp = 5R/2

Explanation:

i. Cv = Molar heat capacity at constant volume

Since the internal energy of the ideal monoatomic gas is U = 3/2RT and Cv = dU/dT

Differentiating U with respect to T, we have

= d(3/2RT)/dT

= 3R/2

ii. Cp - Molar heat capacity at constant pressure

Cp = Cv + R

substituting Cv into the equation, we have

Cp = 3R/2 + R

taking L.C.M

Cp = (3R + 2R)/2

Cp = 5R/2

3 0
3 years ago
"Compared to infrared radiation, does ultraviolet radiation have longer or shorter wavelengths? Does ultraviolet radiation have
balu736 [363]

Answer:Ultraviolet radiation has shorter wavelengths and higher energy than infrared radiation.

Explanation: Electromagnetic radiation radiations which have both electrical and magnetic properties,they can be transmitted through space or through a medium.

It includes Gamma radiation, infra-red, visible light, Ultraviolet radiation etc they occur with different wavelength, the lower the wavelength the higher the Energy dissipated per photon. According to their order of decreasing wavelength and increased energy they are classified as follows.

RADIO WAVE, MICRO WAVE, INFRA-RED, VISIBLE LIGHT, ULTRAVIOLET RAY, X-RAY, GAMMA RAYS.

5 0
3 years ago
A 6,000N is applied to a formula one car that weighs 500kg. What is the car's acceleration?
Vesna [10]

Answer:

<h2>12 m/s²</h2>

Explanation:

The acceleration of an object given it's mass and the force acting on it can be found by using the formula

a =  \frac{f}{m}  \\

f is the force

m is the mass

From the question

f = 6000 N

m = 500 kg

We have

a =  \frac{6000}{500}  =  \frac{60}{5}  = 12 \\

We have the final answer as

<h3>12 m/s²</h3>

Hope this helps you

8 0
3 years ago
An infrared spectrometer on Dawn found something unexpected on Ceres's surface. Its presence suggested that Ceres might have for
Sati [7]

The question is missing alternatives. Here is the complete question.

An infrared spectrometer on Dawn found something unexpected on Ceres's surface. Its presence suggested that Ceres might have formed farther from the Sun, or been impacted by objects from a more-distant part of the solar system. What was this finding?

1. The fact that Ceres is covered with small dark particles  that appear identical to the composition of Uranus's rings.

2. The presence of a thick cloud layer made of sulfuric acid, similar to what is observed at Venus.

3. The presence of clay-like minerals with ammonia bound up in them.

4. The infrared spectrum of Ceres's surface is essentially identical to that of most objects in the Kuiper Belt.

Answer: 3. The presence of clay-like minerals with ammonia bound up in them.

Explanation: The discovery of ammonia clay-like minerals in Ceres is surprising because it would be encoutered in planets that are far from the Sun, since ammonia requires colder temperatures, which is found beyond Jupiter's orbit, to condense. This finding can ascertain not only the origins of the dwarf planet as how the solar system was formed, were organized and evolved, because understanding where smaller planets are formed is important to determine their destiny.

6 0
3 years ago
Other questions:
  • In order for an object to sink, its density must ___________ 1g/ml.
    7·2 answers
  • True or false The momentum of a 100kg object traveling at 3 m/s is 300 N
    5·1 answer
  • A wave has a period of 2 seconds and a wavelength of 4 meters.Calculate its frequency and speed.
    10·2 answers
  • How does the force exerted by two magnets change as the magnets are moved farther apart?
    5·1 answer
  • What is the approximate radius of pluto
    9·2 answers
  • A force in the + x-direction with magnitude F(x) = 18.0N -(0.530 N/m)x is applied to a 6.00-kg box that is sitting on the horizo
    8·1 answer
  • A projectile is launched horizontally from a height of 8.0 m. The projectile travels 6.5 m before hitting the ground.
    7·1 answer
  • 5x - 1 1 - 2x<br>3<br>5<br>11.152<br>&lt;8+2​
    5·1 answer
  • Images formed by a convex mirror are always ​
    10·1 answer
  • PLEASE HELP AS SOON AS POSSIBLE!!
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!