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
qwelly [4]
2 years ago
9

A 150.0-kg crate rests in the bed of a truck that slows from 50.0 km/h to a stop in 12.0 s. The coefficient of static friction b

etween the crate and the truck bed is 0.645. What is the minimum stopping time for the truck in order to prevent the crate from sliding?
Physics
1 answer:
Leokris [45]2 years ago
8 0

By Newton's second law,

• the net force acting vertically on the crate is 0, and

∑ <em>F</em> = <em>n</em> - <em>mg</em> = 0   ==>   <em>n</em> = <em>mg</em> = 1470 N

where <em>n</em> is the magnitude of the normal force; and

• the net force acting in the horizontal direction on the crate is also 0, with

∑ <em>F</em> = <em>f</em> - <em>b</em> = 0   ==>   <em>b</em> = <em>f</em> = <em>µn</em> = 0.645 (1470 N) = 948.15 N

where <em>b</em> is the magnitude of the braking force, <em>f</em> is (the maximum) static friction, and <em>µ</em> is the coefficient of static friction. This is to say that static friction has a maximum magnitude of 948.15 N. If the brakes apply a larger force than this, then the crate will begin to slide.

Note that we are taking the direction of the truck's motion as it slows down to be the positive horizontal direction. The brakes apply a force in the negative direction to slow down the truck-crate system, and static friction keeps the crate from sliding off the truck bed so that the frictional force points in the positive direction.

Let <em>a</em> be the acceleration felt by the crate due to either the brakes or friction. Use Newton's second law again to solve for <em>a</em> :

<em>f</em> = <em>ma</em>   ==>   <em>a</em> = (948.15 N) / (150.0 kg) = 6.321 m/s²

With this acceleration, the truck will come to a stop after time <em>t</em> such that

0 = 50.0 km/h - (6.321 m/s²) <em>t</em>   ==>   <em>t</em> ≈ (13.9 m/s) / (6.321 m/s²) ≈ 2.197 s

and this is the smallest stopping time possible.

You might be interested in
What is the equivalent of 0° C in Kelvin?<br> Help will give brainiest
givi [52]

Answer:

273.15 dat is the answer im pretty sure

8 0
3 years ago
Varg sees a spring that has a spring constant of 4 N/m that is stretched 5 m. He stretches the spring an additional 5 m. Conside
AysviL [449]

Answer:

Elastic potential energy, E = 200 J

Explanation:

It is given that,

Spring constant, K = 4 N/m

initial stretching in the spring, x = 5 m

Finally, it is stretched an additional 5 m i.e. x' = 5 m        

Let E is the elastic energy in the spring after Varg stretches the spring. it is given by :

E=\dfrac{1}{2}k(x+x')^2

E=\dfrac{1}{2}\times 4\times (10)^2

E = 200 J

So, the elastic energy in the spring after Varg stretches the spring is 200 J. hence, this is the required solution.

8 0
3 years ago
Read 2 more answers
Which statements best characterize conductors? Check all that apply.
romanna [79]
It would be the first one and the third one
5 0
3 years ago
Read 2 more answers
Particle motion in surface waves is __________ motion.
gulaghasi [49]
<h3>Answer;</h3>

<em>B.)neither longitudinal nor transverse</em>

<h3><u>Explanation;</u></h3>
  • <em><u>Longitudinal waves</u></em> are waves in which the vibration of particles is parallel to the direction of the wave motion.
  • <em><u>Transverse waves</u></em> on the other hand are those waves in which the vibration of particles is perpendicular to the direction of the wave motion.
  • In <em><u>surface waves particles in the medium of transmission move in a circular motion.</u></em> Therefore, they are neither transverse waves nor longitudinal waves.
7 0
3 years ago
Read 2 more answers
An electron in a mercury atom drops
aksik [14]

Since the electron dropped from an energy level i to the ground state by emitting a single photon, this photon has an energy of 1.41 × 10⁻¹⁸ Joules.

<h3>How to calculate the photon energy?</h3>

In order to determine the photon energy of an electron, you should apply Planck-Einstein's equation.

Mathematically, the Planck-Einstein equation can be calculated by using this formula:

E = hf

<u>Where:</u>

  • h is Planck constant.
  • f is photon frequency.

In this scenario, this photon has an energy of 1.41 × 10⁻¹⁸ Joules because the electron dropped from an energy level i to the ground state by emitting a single photon.

Read more on photons here: brainly.com/question/9655595

#SPJ1

4 0
2 years ago
Other questions:
  • Anything that moves up and down or back and forth in a rhythmic way is vibrating true false
    11·2 answers
  • Which of the following best describes a plane?
    10·2 answers
  • Can someone help me on #18 - #26? At least one ☝️ I really need help!!!
    10·1 answer
  • Water at a gauge pressure of 3.8 atm at street level flows in to an office building at a speed of 0.06 m/s through a pipe 5.0 cm
    5·2 answers
  • How would you classify the wave?
    6·2 answers
  • How is energy related to the change of state represented by the model?
    7·2 answers
  • Select all of the answers that apply. Which of the following make the Earth unique when compared to the other planets in our sol
    14·1 answer
  • Which of the following is NOT an insulator?
    7·2 answers
  • Where is cloud data stored?
    5·2 answers
  • A town is considering building a biodiesel power plant that would burn biomass to generate electricity. Which of the following c
    8·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!