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
rodikova [14]
3 years ago
7

A car is safely negotiating an unbanked circular turn at a speed of 25 m/s. The road is dry, and the maximum static frictional f

orce acts on the tires. Suddenly a long wet patch in the road decreases the maximum static frictional force to one third of its dry-road value. If the car is to continue safely around the curve, to what speed must the driver slow the car?
Physics
1 answer:
Brums [2.3K]3 years ago
8 0

Answer:

The velocity must be reduced to one third to stay on the road

Explanation:

The sideways force that friction must resist comes from the centrifugal acceleration due to the turn.

fc=mv2Rfc=mv2R

the frictional force is given by

ff=μmgff=μmg where μμ is the static friction coefficient

if the car is not to skid

fc≤fffc≤ff so    

mv2R≤μmgmv2R≤μmg

v≤μgR−−−−√v≤μgR

thus vv varies as the square root of μμ

so if μμ is reduced by 9, vv must be reduced by 9–√=39=3

and thus the speed must be reduced to<u> 26</u> m/s

                                                                    3

You might be interested in
A rod made up of certaon metall which had coefficiebt of volume expansion is 33×10^-6 per celsius degrer.The rod is 100 meter lo
Irina-Kira [14]

Answer:

100.11 m

Explanation:

Given:

Coefficient of volume expansion, \alpha_{v}=33\times10^{-6} /°C.

Initial length of rod, l=100 m

Change in temperature, ΔT=(90-(-10))=100 °C

We know that,

\alpha_{v}=3\alpha_{L}\\\alpha_{L}=\frac{\alpha_{v}}{3}\\\alpha_{L}=\frac{33\times10^{-6}}{3}=11\times10^{-6} /°C

Here, \alpha_{L} is the coefficient of linear expansion.

Now, we know that,

Change in length (Δl) is given as,

\Delta l=\alpha_L\times L\times\Delta T

Plug in all the values and solve for l.

This gives,

\Delta l=11\times10^{-6}\times 100\times100\\\Delta l=0.11 \textrm{ m}

Therefore, the length of rod after expansion is L+\Delta l=100+0.11=100.11 m.

4 0
3 years ago
A closely wound circular coil has a radius of 6.00 cmand carries a current of 2.65 A. How many turns must it have if the magneti
ad-work [718]

Answer:

Given:

radius of the coil, R = 6 cm = 0.06 m

current in the coil, I = 2.65 A

Magnetic field at the center, B = 6.31\times 10^{4} T

Solution:

To find the number of turns, N, we use the given formula:

B = \frac{\mu_{o}NI}{2R}

Therefore,

N = \frac{2BR}{\mu_{o}I}

N = \frac{2\times 6.31\times 10^{4}\times 0.06}{4\pi \times 10^{- 7}\times 2.65}

N = 22.74 = 23 turns (approx)

 

8 0
3 years ago
a horizontal clothesline is tied between 2 poles, 10 meters apart. when a mass of 1 kilograms is tied to the middle of the cloth
natali 33 [55]

By analyzing the vector, the clothesline tension is 25 N.

We need to know about vectors to solve this problem. Force is included in vectors that have magnitude and direction. It can be written as

F = (Fx i + Fy j) N

where F is the force vector, Fx is the x-axis component and Fy is the y-axis component.

From the question we know that :

x = 10 m

(midpoint = 5m)

y = 1 m

m = 1 kg

Find the weight

W = m . g

W = 1 x 10

W = 10N

There are two y-axis components of the tension that hold the clothes. Because of static conditions, we can write

∑Fy = 0

Ty + Ty - W = 0

2Ty - 10 = 0

2Tsinθ - 10 = 0

Find sinθ

sinθ = y/x

sinθ = 1/5

Substitute the sinθ

2Tsinθ - 10 = 0

2T(1/5) - 10 = 0

2T/5 = 10

T = 25 N

Hence, the clothesline tension is 25 N.

For more about vectors at: brainly.com/question/25811261

#SPJ4

6 0
1 year ago
What will be the weight of a box, mass 10Kg on the surface of a hypothetical planet having mass double of Earth and the radius i
vlada-n [284]

Answer:

           W ’= 21.78 kg

Explanation:

The expression for weight is

          W = m g

let's look for the acceleration of gravity with the universal law of gravitation

          F = G m M / r2

          F = m (G M / r2)

without comparing the two equations

          g’= G M / r2

in that case M = 2 Mo and r = 3 ro

where mo and ro are the mass and radius of the earth

         we substitute

         g ’= G 2Mo / (3r₀) 2

         G ’= 2/9 G Mo / r₀²

         g ’= 2/9 g

the weight of the body on this planet is

         W ’= m g’

          W ’= m 2/9 g

let's calculate

          W ’= 2/9 10 9.8

           W ’= 21.78 kg

3 0
3 years ago
A planet with half Earth’s mass and half Earth’s radius is discovered. What would an astronaut who weighs 800 N on Earth weigh o
Citrus2011 [14]
1600 N
Hope this helped !
5 0
3 years ago
Other questions:
  • A cattleman has installed a new electric fence. The cows keep escaping because they are not deterred by the low power they exper
    5·2 answers
  • I need to know what a-e is. Please and thank you!
    6·1 answer
  • An train car of total mass of 13000 kg is pulling into a station and slowing down with an acceleration of -4.56 m/s^2. Before th
    10·1 answer
  • Question 1(Multiple Choice Worth 4 points) The star named Canopus has a declination of approximately –52°. Which of these statem
    14·1 answer
  • A pure substance can be a ..................... (a) element (b) compound (c) either element or compound (d)none of these
    11·2 answers
  • If an upstairs room is warmer than downstairs, is that a example of convection, conduction, or radiation?
    14·1 answer
  • an underground cannon launches a cannonball from ground level at a 35-degree angle. the cannonball is shot with an initial veloc
    7·1 answer
  • A ceiling fan has 5-inch blades (so the radius of the circular fan is inches). Suppose the fan turns at a rate of 2 revolutions
    11·1 answer
  • What is the internal resistance of a current source with an EMF of 12 V if, when a resistor with an unknown resistance is connec
    8·1 answer
  • ENERGY AND FORCES UNIT TEST CONNECTIONS ACADEMY
    6·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!