Advertisements
Advertisements
प्रश्न
Answer in brief:
Why are curved roads banked?
Advertisements
उत्तर
- When a car makes a turn, it moves in a circular manner. The necessary centripetal force is the static friction force between the car tyres and the road surface if the road is level (or horizontal).
- The amount of friction is determined by the nature of the surfaces that come into contact, as well as the presence of oil and water on the road. If the friction is insufficient, a speeding car may skid off the road. Because friction varies depending on the situation, it cannot be relied upon to generate the required centripetal force. Furthermore, friction causes rapid tyre wear and tear.
- To avoid the risk of sliding and the wear and tear on car tyres, the road surface at a bend is tilted inward, i.e., the outer side of the road is raised over the inner side. This is known as road banking. On a banked road, the result of the normal reaction and gravitational force can serve as the required centripetal force. As a result, any car can be driven safely on such a banked curve at an ideal speed without relying on friction. As a result, at a bend, a road should be correctly banked.
- The angle of banking is the angle of inclination of a banked road's surface at its end with the horizontal.
APPEARS IN
संबंधित प्रश्न
On what factors does the frequency of a conical pendulum depend? Is it independent of some factors?
Somehow, an ant is stuck to the rim of a bicycle wheel of diameter 1 m. While the bicycle is on a central stand, the wheel is set into rotation and it attains the frequency of 2 rev/s in 10 seconds, with uniform angular acceleration. Calculate:
- The number of revolutions completed by the ant in these 10 seconds.
- Time is taken by it for first complete revolution and the last complete revolution.
Answer in Brief:
A flywheel used to prepare earthenware pots is set into rotation at 100 rpm. It is in the form of a disc of mass 10 kg and a radius 0.4 m. A lump of clay (to be taken equivalent to a particle) of mass 1.6 kg falls on it and adheres to it at a certain distance x from the center. Calculate x if the wheel now rotates at 80 rpm.
A big dumb-bell is prepared by using a uniform rod of mass 60 g and length 20 cm. Two identical solid spheres of mass 25 g and radius 10 cm each are at the two ends of the rod. Calculate the moment of inertia of the dumb-bell when rotated about an axis passing through its centre and perpendicular to the length.
Does the angle of banking depend on the mass of the vehicle?
A hollow sphere has a radius of 6.4 m. what is the minimum velocity required by a motorcyclist at the bottom to complete the circle.
A bend in a level road has a radius of 100m. find the maximum speed which a car turning this bend may have without skidding if the coefficient of friction between the tires and road is 0.8.
Derive an expression for maximum safety speed with which a vehicle should move along a curved horizontal road. State the significance of it.
A bucket containing water is tied to one end of a rope 5 m long and it is rotated in a vertical circle about the other end. Find the number of rotations per minute in order that the water in the bucket may not spill.
A body weighing 0.5 kg tied to a string is projected with a velocity of 10 m/s. The body starts whirling in a vertical circle. If the radius of the circle is 0.8 m, find the tension in the string when the body is at the top of the circle.
Derive an expression for the kinetic energy of a rotating body with uniform angular velocity.
A railway track goes around a curve having a radius of curvature of 1 km. The distance between the rails is 1 m. Find the elevation of the outer rail above the inner rail so that there is no side pressure against the rails when a train goes around the curve at 36 km/hr.
What is a conical pendulum? Obtain an expression for its time period
Obtain an expression for maximum safety speed with which a vehicle can be safely driven along a curved banked road.
A rigid body rotates with an angular momentum L. If its kinetic energy is halved, the angular momentum becomes, ______
A particle undergoes uniform circular motion. The angular momentum of the particle remains conserved about, ______
What is the relation between torque and angular momentum?
Discuss conservation of angular momentum with example.
A uniform metallic rod rotates about its perpendicular bisector with constant angular speed. If it is heated uniformly to raise its temperature to a certain value, its speed of rotation ______.
A wheel of radius 2 cm is at rest on the horizontal surface. A point P on the circumference of the wheel is in contact with the horizontal surface. When the wheel rolls without slipping on the surface, the displacement of point P after half rotation of wheel is ______.
A ring and a disc of different masses are rotating with the same kinetic energy. If we apply a retarding torque τ on the ring, it stops after completing n revolution in all. If the same torque is applied to the disc, how many revolutions would it complete in all before stopping?
What is the difference between rotation and revolution?
