Acurve of radius 78m is banked for design speed of 85km/h. if coeficient of static friction is 0.3[wet pavement]at what range of speeds can a car safelymake the curve?

The speed of the car safely make the curve, V = 65.23 Km/h

Explanation:

Given,

The radius of the curve, r = 78 m

The designed speed of the curve, v = 85 km/h

                                                            = 23.61 m/s

The coefficient of static friction, μₓ = 0.3

The static friction of the curve is given by the relation,

                                       Fₓ = μₓ η

The acceleration responsible for the static friction

                                      aₓ  = μₓ x g

Substituting the values in the equation

                                      aₓ = 0.3 x 9.8

                                           = 2.94 m/s²

The designed acceleration of the curve

                                        a₀ = v²/r

                                           = 23.61²/78

                                          = 7.15  m/s²

The acceleration supported by the static friction, aₓ can be subtracted from the designed acceleration of the curve.

Therefore the net acceleration,

                                         a  = a₀ - aₓ

                                             = 7.15 - 2.94

                                              = 4.21 m/s²

The centripetal velocity associated with this acceleration is

                                           a = V²/r

∴                                         V² = a x r

                                          V = √(a x r)

                                              =√ (4.21 x 78)

                                               = 18.12 m/s      

                                               = 65.23 Km/h

Hence, the speed required by the car to safely make the curve is, V = 65.23 Km/h                                

true is the correct answer

hope i

-first use of geothermal energy occurred more than 10,000 years ago in north america by american paleo-indians

-the first industrial use of geothermal energy began near pisa, italy in late 18th century

-in 1904, italian scientist piero ginori conti invented the first geothermal electric power plant in which steam was used to generate the power

-with the above experiment, the first geothermal plant in usa started in 1922 with a capacity of 250 kilowatts

-however, in 1946 first ground-source geothermal heat pump installed at commonwealth building in portland, oregon

-during the 1960’s, pacific gas and electric began operation of first large scale geothermal power plant in san francisco, producing 11 megawatts

-in 1973, when oil crisis began many countries began looking for renewable energy sources and by 1980’s geothermal heat pumps (ghp) started gaining popularity in order to reduce heating and cooling costs

-as effect of climate change started showing results, governments of various countries joined hands to fight against it, for which kyoto protocol was signed in japan in 1997, laid out emission targets for rich countries and required that they transfer funds and technology to developing countries, 184 countries have ratified it

hope this