Circular motion of a car on a banked road

[MIN JIN]

Homework Statement

A car of mass 1120 kg is travelling along a curved UN banked road of radius 60 m. Its wheel tract is 135 m and its center of gravity is 0.9 m above the ground, and midway between front and rear axles. The coefficient of friction is 0.5. Find (a) the vertical ground reaction at each wheel when the car is travelling at 15 m/s; (b) the maximum speed without overturning; (c) the skidding speed.

Relevant Equations

f=(m v^2)/r
w=mg
f=u w

f=(m v^2)/r

 

[Cutter Ketch]

You will have to make an attempt before anyone can help you

 

[MIN JIN]

oh i did ,,, lots of times

 

[MIN JIN]

i can't get the answer right ,, took the question from hannah and hillier

 

[Cutter Ketch]

oh i did ,,, lots of times

Let rephrase: you will have to show us an attempt before we can help.

 

[MIN JIN]

 

[MIN JIN]

please help ,,, been at it for the whole day !

 

[MIN JIN]

Let rephrase: you will have to show us an attempt before we can help.

alright ,,lemme take pictures of my "ATTEMPTS"

 

[MIN JIN]

alright ,,lemme take pictures of my "ATTEMPTS"

 

[MIN JIN]

(b) and (c) are fine , its the reactions at the tires that i do not get

 

[MIN JIN]

Someone pleaasee crack question a.

 

[Lnewqban]

Someone pleaasee crack question a.

Beginning with question a):
Revise the reactive forces that your car "feels" on the two left and two right tires.
There are vertical forces, let's name those $R_ya$ and $R_yb$
There are horizontal forces, let's name those $R_xa$ and $R_xb$

In order to determine the values of those vertical forces, you will need to add up all the horizontal forces, all the vertical forces and all the moments, all of which should equal zero, since the car is in a dynamic balance.
From those three equations, you will be able to calculate the requested vertical forces.

 

[haruspex]

(b) and (c) are fine , its the reactions at the tires that i do not get

Then why did you post your (successful) attempts at b) and c) but not an attempt at a)?

 

[MIN JIN]

Beginning with question a):
Revise the reactive forces that your car "feels" on the two left and two right tires.
There are vertical forces, let's name those $R_ya$ and $R_yb$
There are horizontal forces, let's name those $R_xa$ and $R_xb$

In order to determine the values of those vertical forces, you will need to add up all the horizontal forces, all the vertical forces and all the moments, all of which should equal zero, since the car is in a dynamic balance.
From those three equations, you will be able to calculate the requested vertical forces.

Thanks so much ,this helped a lot , i found it

 

[MIN JIN]

Turns i simply forgot the fact that the're 2 inner wheels and 2 outer ones , total of four ,, had to find reactions at "EACH" WHEEL ,not a pair.