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
Snowcat [4.5K]
3 years ago
10

A flat (unbanked) curve on a highway has a radius of 240.0 m m . A car rounds the curve at a speed of 26.0 m/s m/s . Part A What

is the minimum coefficient of friction that will prevent sliding? μ min μmin = nothing SubmitRequest Answer Part B Suppose the highway is icy and the coefficient of friction between the tires and pavement is only one-third what you found in part A. What should be the maximum speed of the car so it can round the curve safely?

Physics
1 answer:
Grace [21]3 years ago
8 0

Answer:

a) u_s=0.375

b )v=14.4 m/s

Explanation:

1 Concepts and Principles

Particle in Equilibrium: If a particle maintains a constant velocity (so that a = 0), which could include a velocity of zero, the forces on the particle balance and Newton's second law reduces to:  

∑F=0                 (1)

2- Particle in Uniform Circular Motion:

If a particle moves in a circle or a circular arc of radius Rat constant speed v, the particle is said to be in uniform circular motion. It then experiences a net centripetal force F and a centripetal acceleration a_c. The magnitude of this force is:

F=ma_c

 =m*v^2/R            (2)

where m is the mass of the particle F and a_c are directed toward the center of curvature of the particle's path.  

<em>3- The magnitude of the static frictional force between a static object and a surface is given by:</em>  

f_s=u_s*n              (3)

where u_s is the coefficient of kinetic friction between the object and the surface and n is the magnitude of the normal force.  

Given Data

R (radius of the car's path) = 170 m

v (speed of the car) = 25 m/s  

Required Data

- In part (a), we are asked to find the coefficient of static friction u_s that will prevent the car from sliding.  

- In part (b), we are asked to find the speed of the car v if the coefficient of static friction is one-third u_s found in part (a).  

Solution:

see the attachment pic

Since the car is not accelerating vertically, we can model it as a particle in equilibrium in the vertical direction and apply Equation (1)

∑F_y=n-mg

       = mg               (4)  

We model the car as a particle in uniform circular motion in the horizontal direction. The force that enables the car to remain in its circular path is the force of static friction at the point of contact between road and tires. Apply Equation (2) to the horizontal direction:

∑F_x=f_s

       =m*v^2/R

Substitute for f_s from Equation (3):  

u_s=m*v^2/R

Substitute for n from Equation (4):  

u_s*mg=m*v^2/R

  u_s*g = v^2/R

Solve for u_s:

u_s=  v^2/Rg                          (5)

Substitute numerical values:  

u_s=0.375

(b)  

The new coefficient of static friction between the tires and the pavement is:

u_s'=u_s/3

Substitute u_s/3 for u_s in Equation (5):

u_s/3=v^2/Rg  

Solve for v:  

v=14.4 m/s

You might be interested in
Suppose all of the apples have a mass of 0.10 kg and one of the apples in the bowl (C) is 1.0 meter off the ground. If the apple
sesenic [268]
The answer is 0.981 J

E = m · g · h<span>
E - energy
m - mass
g - gravitational acceleration
h - height

We know:
E = ?
m = 0.10 kg
g = 9.81 m/s</span>²
h = 1 m

E = 0.10 kg * 9.81 m/s² * 1 m = 0.981 J
6 0
3 years ago
Read 2 more answers
Charges of 4.0 μC and −6.0 μC are placed at two corners of an equilateral triangle with sides of 0.10 m. What is the magnitude o
jek_recluse [69]

Answer:

4.763 × 10⁶ N/C

Explanation:

Let E₁ be the electric field due to the 4.0 μC charge and E₂ be the electric field due to the -6.0 μC charge. At the third corner, E₁ points in the negative x direction and E₂ acts at an angle of 60 to the negative x - direction.

Resolving E₂ into horizontal and vertical components, we have

E₂cos60 as horizontal component and E₂sin60 as vertical component. E₁ has only horizontal component.

Summing the horizontal components we have

E₃ = -E₁ + (-E₂cos60) = -kq₁/r²- kq₂cos60/r²

= -k/r²(q₁ + q₂cos60)

= -k/r²(4 μC + (-6.0 μC)(1/2))

= -k/r²(4 μC - 3.0 μC)

= -k/r²(1 μC)

= -9 × 10⁹ Nm²/C²(1.0 × 10⁻⁶)/(0.10 m)²

=  -9 × 10⁵ N/C

Summing the vertical components, we have

E₄ = 0 + (-E₂sin60)

= -E₂sin60

= -kq₂sin60/r²

= -k(-6.0 μC)(0.8660)/(0.10 m)²

= -9 × 10⁹ Nm²/C²(-6.0 × 10⁻⁶)(0.8660)/(0.10 m)²

= 46.77 × 10⁵ N/C

The magnitude of the resultant electric field, E is thus

E = √(E₃² + E₄²) = √[(-9 × 10⁵ N/C)² + (46.77 10⁵ N/C)²) = (√226843.29) × 10⁴

= 476.28  × 10⁴ N/C

= 4.7628 × 10⁶ N/C

≅ 4.763 × 10⁶ N/C

8 0
3 years ago
If the marshmallows represent the atoms in the substance, which change of state is Freida modeling Freida wants to model the way
sashaice [31]

Answer: Melting

Explanation:

When Frieda made a pyramid of marshmallows, she was representing the atoms in a solid substance as the atoms are clumped together and unable to move.

When she then knocks it down, she is showing the movement of atoms in a liquid substance as they are now freer than they were before. The process by which substances go from solid to liquid is melting.

7 0
3 years ago
Read 2 more answers
What net force acting on a 14 KG wagon produces an acceleration of 1.5 MS^2?
valentina_108 [34]

21N

Explanation:

Given parameters:

Mass of wagon = 14kg

Acceleration = 1.5m/s²

Unknown:

Net force on wagon = ?

Solution:

Force is a pull or push on a body that causes a body to change its state. It is expressed as:  

                 Force = mass  x acceleration

  Force on wagon = 14 x 1.5 = 21N

Learn more:

Force brainly.com/question/10470406

#learnwithBrainly

7 0
3 years ago
What do you mean by Parallel Universe ?​
BartSMP [9]

Answer:

Parallel universe, or alternate reality, is a hypothetical self-contained plane of existence, co-existing with one's own

3 0
3 years ago
Read 2 more answers
Other questions:
  • Consider three starships that pass by an observer on Earth. Starship A is traveling at speed v=c/3v=c/3 relative to Earth and ha
    13·1 answer
  • Based on how stars are named, which star is probably brightest
    11·2 answers
  • A flywheel of diameter 1.2 m has a constant angular acceleration of 5.0 rad/s2. the tangential acceleration of a point on its ri
    6·1 answer
  • Describe what an electromagnet
    8·2 answers
  • The driver of a car traveling at 23.1 m/s applies the brakes and undergoes a constant
    13·1 answer
  • Two identical circular, wire loops 48.0 cm in diameter each carry a current of 4.50 A in the same direction. These loops are par
    10·1 answer
  • You decide to do an experiment to investigate Newton's Third Law. Below are several
    5·1 answer
  • An insulator________the loss of heat energy.
    9·2 answers
  • A lawyer most likely has __________. a.spatial intelligence b.practical intelligence c.analytical intelligence d.creative intell
    12·1 answer
  • Use the same line to answer the questions
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!