I in finding correct Coefficient of friction

[akki2063]

A road vehicle equipped with mechanical wheel brake e.g drum or disc brake ,driving at a speed of 100Km/hr is braked to a stand still with a deceleration of 1G (3.2m/sec^2),How large must be the coefficient if friction between wheel and road at least be to enable that.

Options:

1)At least 1.
2)0.5
3)2

 

[Mentz114]

The force exerted on the truck when the brakes come on ( and lock the wheels) is mg, g=3.2ms^-2 and m is the trucks mass.

Can you calculate the force provided by the friction in terms of the coefficient of friction ?

(Incidentally the acceleration on the Earth's surface is about 9.7ms^-2, not 3.2)

 

[berkeman]

A road vehicle equipped with mechanical wheel brake e.g drum or disc brake ,driving at a speed of 100Km/hr is braked to a stand still with a deceleration of 1G (3.2m/sec^2),How large must be the coefficient if friction between wheel and road at least be to enable that.

Options:

1)At least 1.
2)0.5
3)2

Check your PMs. You *must* show your efforts before we can provide tutorial help. That is in the PF Rules (see the top of the page under Site Info).

 

[SteamKing]

The force exerted on the truck when the brakes come on ( and lock the wheels) is mg, g=3.2ms^-2 and m is the trucks mass.

Can you calculate the force provided by the friction in terms of the coefficient of friction ?

(Incidentally the acceleration on the Earth's surface is about 9.7ms^-2, not 3.2)

I don't know where you got g = 9.7 m/s^2, but there is a different and more precise figure defined:

http://en.wikipedia.org/wiki/Standard_gravity

 

[Nickie]

Based on the given information, the coefficient of friction between the wheel and the road must be at least 0.5 to enable the vehicle to come to a complete stop with a deceleration of 1G. This value may vary depending on the specific design and conditions of the vehicle's braking system, but a minimum of 0.5 is necessary to achieve the desired result. It is important to note that other factors such as tire tread and road surface can also affect the coefficient of friction and should be taken into consideration when determining the appropriate value for a specific vehicle.