Title UNIFORM CIRCULAR MOTION.pdf ✅

www.teachersofphysics.com Copyright © 2020 12. State two factors which determine the maximum speed at which a car can successfully negotiate a corner on a banked road.  Radius of the bend should be bigger.  Angle of banking should be bigger.  Surface of the road should be rough. 13. State the condition necessary for a car traveling on a banked road not to skid.  The critical speed should not be exceeded. 14. Explain why a pail of water can be swung in a vertical circle without the water pouring out.  This is because the centripetal force acting on the water in the vertical position is greater than the weight of the water. 15. State the reason why banking of a circular part of road is necessary.  Banking provides sufficient centripetal friction that keeps the body on a circular path without skidding off. 16. A body of mass m kg moves uniformly around a circle of radius r m with a linear velocity v m/s. Derive an expression for the relationship between its linear velocity v and angular velocity ω. Angular displacement = arc lenth s radius r θ = s r Angular velocity, ω, = change in disp. change in time i. e ω = ∆θ ∆t , but θ = s r → θ t = s rt Thus ∆θ ∆t = ∇s r∆t ; but ω = ∆s ∆t and ∆s r∆t = v r Hence ω = v r → v = ωr From definition;
www.teachersofphysics.com Copyright © 2020 17. A cyclist negotiating a corner at a high speed leans inwards in order to successfully pass. Explain how this action enables him to negotiate.  Leaning inwards produces the turning effect in the clockwise and anti-clockwise because of the normal and frictional forces thus providing sufficient centripetal force. 18. A sports car negotiates a corner on a banked road at very high velocity. i. What is meant by the term banked road?  This is a road that has the outer part slightly raised above the inner side so that the track is slopping towards the center of the curve. ii. Name two factors which determine the magnitude of its velocity.  Radius of the corner.  Banking angle.  Nature of the road surface. iii. What provides the centripetal force on the car?  Frictional force between the car tyres and the surface of the road OR Horizontal component of reaction force. 19. What provides for the centripetal force the following cases of circular motion? a) The moon moving around the earth.  Force of attraction between the earth and the moon. b) A cyclist negotiating a curve.  Frictional force between the tyre and the surface of the curve. 20. When is a satellite said to be in a “parking orbit”?  If its periodic time is equal to that of the earth. 21. State the factors affecting the centripetal force and Explain how each of the factors affect the centripetal force. a. Mass of the body → , . b. Angular velocity of the object → , c. Radius of the path →