मराठी
महाराष्ट्र राज्य शिक्षण मंडळएचएससी विज्ञान (सामान्य) इयत्ता १२ वी

A road is constructed as per the given requirements. The coefficient of static friction between the tyres of a vehicle on this road is 0.8, will there be any lower speed limit? By how much can the - Physics

Advertisements
Advertisements

प्रश्न

A road is constructed part of a racing tracks to be designed with radius of curvature 72 m. We are not recommending the vehieles to drive faster than 216 kmph.. The coefficient of static friction between the tyres of a vehicle on this road is 0.8, will there be any lower speed limit? By how much can the upper speed limit exceed in this case?

(Given: r = 72 m, vo = 216 km/h, w = 10 m, θ = 78°4', h = 9.805 m)

संख्यात्मक
Advertisements

उत्तर

Given:

μs = 0.8

r = 72 m

θ = 78°4'

g = 10 m/s2 

tan θ = tan 78°4' = 5

Vmin = `sqrt("rg"[("tan "theta - mu_"s")/(1 + mu_"s" "tan "theta)])`

= `sqrt(72 xx 10((5 - 0.8)/(1 + 0.8 xx 5)))`

`= sqrt(720 xx 4.2/(4 + 1)`

`= sqrt(3024/5)`

`= sqrt(144 xx 4.2)`

= 12 × 2.049

= 24.588 m/s

= 88.52 km/h

This will be the lower limit or minimum speed on this track.

Since the track is heavily banked, θ > 45°, there is no upper limit or maximum speed on this track.

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 1: Rotational Dynamics - Exercises [पृष्ठ २५]

APPEARS IN

बालभारती Physics [English] Standard 12 Maharashtra State Board
पाठ 1 Rotational Dynamics
Exercises | Q 15 | पृष्ठ २५

संबंधित प्रश्‍न

Answer in Brief:

Part of a racing track is to be designed for curvature of 72m. We are not recommending the vehicles to drive faster than 216 kmph. With what angle should the road be tilted? By what height will its outer edge be, with respect to the inner edge if the track is 10 m wide?


During a stunt, a cyclist (considered to be a particle) is undertaking horizontal circles inside a cylindrical well of radius 6.05 m. If the necessary friction coefficient is 0.5, how much minimum speed should the stunt artist maintain? The mass of the artist is 50 kg. If she/he increases the speed by 20%, how much will the force of friction be?


A metallic ring of mass 1 kg has a moment of inertia 1 kg m2 when rotating about one of its diameters. It is molten and remolded into a thin uniform disc of the same radius. How much will its moment of inertia be, when rotated about its own axis.


Using the energy conservation, derive the expressions for the minimum speeds at different locations along a vertical circular motion controlled by gravity. Is zero speed possible at the uppermost point? Under what condition/s?


A vehicle of mass m is moving with momentum p on a rough horizontal road. The coefficient of friction between the tyres and the horizontal road is µ. The stopping distance is ____________.

(g = acceleration due to gravity)


For a body moving with constant speed in a horizontal circle, which of the following remains constant?


A horizontal circular platform of mass 100 kg is rotating at 5 r.p.m. about vertical axis passing through its centre. A child of mass 20 kg is standing on the edge of platform. If the child comes to the centre of platform then the frequency of rotation will become ______.


A pendulum has length of 0.4 m and maximum speed 4 m/s. When the length makes an angle 30° with the horizontal, its speed will be ______.
`[sin  pi/6 = cos  pi/3 = 0.5 and "g" = 10 "m"//"s"^2]`


A body of mass 10 kg is attached to a wire 0.3 m long. Its breaking stress is 4.8 × 10N/m2. The area of cross-section of the wire is 10-6m2. The maximum angular velocity with which it can be rotated 111 a horizontal circle is ______.


A particle moves along a circular path of radius 'r' with uniform speed 'V'. The angle described by the particle in one second is ______.


In the case of conical pendulum, if 'T' is the tension in the string and 'θ' is the semi-vertical angle of cone, then the component which provides necessary centripetal force is ______.


A particle rotates in horizontal circle of radius ‘R’ in a conical funnel, with speed ‘V’. The inner surface of the funnel is smooth. The height of the plane of the circle from the vertex of the funnel is ______.

(g = acceleration due to gravity)


A particle executes uniform circular motion with angular momentum 'L'. Its rotational kinetic energy becomes half when the angular frequency is doubled. Its new angular momentum is ______.


The two blocks, m = 10 kg and M = 50kg are free to move as shown. The coefficient of static friction between the blocks is 0.5 and there is no friction between M and the ground. A minimum horizontal force F is applied to hold m against M that is equal to ______.


The centripetal acceleration of the bob of a conical pendulum is, in the usual notation, ______.


A cyclist is undertaking horizontal circles inside a cylindrical well of radius 5 m. If the friction coefficient is 0.5, what should be the minimum speed of the cyclist?


Write about the kinetic friction between the road and the tyres.


The radius of curvature of road is 60 m. If angle of banking is 27°, find maximum speed with which vehicle can tum along this curve. . (g = 9.8 m/s2)


A body performing uniform circular motion has ______.


Why does a motorcyclist moving along a level curve at high speed have to lean more than a cyclist moving along the same curve at low speed?


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×