A small car with mass m and speed 2v and a large car with mass 2m and speed v both travel the same circular section of an unbanked road. If the frictional; force required to keep the small car on the road without skidding is F, then the frictional force required to keep the large car on the road without skidding is

(A) 4F
(B) 2F
(C) F
(D) F/2
(E) F/4

Respuesta :

Answer:

(D) F/2

Explanation:

Since the circular section is unbanked, the centripedal acceleration acting on each of the cars is

[tex]a_s = \frac{v_s^2}{r} = \frac{(2v)^2}{r} = \frac{4v^2}{r}[/tex]

[tex]a_l = \frac{v_l^2}{r} = \frac{v^2}{r}[/tex]

Therefore the centripetal force on each car

[tex]F_s = m_sa_s = \frac{4mv^2}{r}[/tex]

[tex]F_l = m_la_l = \frac{2mv^2}{r}[/tex]

Since [tex]F_s = 2F_l[/tex] this means the friction force required to keep the large car on the road is only half of the friction force required to keep the small car on road

So (D) F/2 is the correct answer

The frictional force required to keep the large car on the road without skidding is (D) F/2.

In this problem the centripetal force is provided by  friction.

The centripetal force for any particle rotating in a circular section is given by equation (1)

[tex]F[/tex] = [tex]m\times V^2/r[/tex].....,,,(1)

where m =  mass of particle

V = Velocity of the particle and

r = Radius of the Circle on which the particle is rotating

Given

There are two cars  

Mass of small car = m

Speed of small car = 2v

so the frictional  force for small car [tex]F_s[/tex] = [tex]m\times (2v)^2/r[/tex]...........(2)  

Mass of large car = 2m

Speed of large car = v

so the frictional  force  for large  car [tex]F_l[/tex] = [tex]2m\times (v)^2/r[/tex]...........(3)

On Dividing equation  (3) by (2)  we get

[tex]F_l[/tex] /[tex]F_s[/tex]  = 1/2

[tex]F_l[/tex] = [tex]F_s[/tex] /2 = F/2  ( Given [tex]F_s[/tex] = F )

so

We can say that

Option D is correct.

For more information please refer the link below :

https://brainly.com/question/1623673