Physics XI Karachi Board True and False - Chapter 4

Chapter 4 - Motion in Two Dimensions
1. The motion of the object along a straight line is called angular motion.

2. The motion of the object along a curved path is called linear motion.

3. Projectile motion is the example of the motion of the body in two dimensions.

4. In projectile motion the object is purely under the influence of force of gravity.

5. In projectile motion the acceleration due to gravity (g) will always be taken as positive.

6. During the projectile motion, the horizontal component of its velocity increases.

7. During the projectile motion, the vertical component of its velocity changes.

8. The path of the projectile is a parabolic path.

9. During the projectile motion the acceleration along horizontal direction is zero.

10. In projectile the acceleration along vertical direction is equal to the acceleration due to gravity.

11. In projectile the acceleration along vertical direction is always constant.

12. The expression for the time to reach the maximum height of the projectile is Vosinq/g.

13. The expression for the total time of flight of the projectile is Vosinq/2g.

14. The expression for maximum height reached by the projectile is Vo2sin2q/2g.

15. The expression for the horizontal range of projectile is Vo2sin2q/2g.

16. The expression for the horizontal range of projectile is Vosinq/2g.

17. For the maximum range of the projectile the angle of elevation must be 45°.

18. The horizontal range of the projectile is directly proportional to the sine of the twice of the angle of elevation.

19. The expression of the trajectory of the projectile is ax-1/2bx2.

20. In projectile the large angle of deviation produces low trajectory.

21. If the angle of elevation of the projectile is 90° then its horizontal range is zero.

22. For the projectile with high trajectory their time of flight will be long.

23. For the projectile with low trajectory their time of flight will be short.

24. If a projectile has some horizontal range at an angle of 15° then its range will be the same when the angle of elevation is 75°.

25. At maximum height the vertical component of the velocity of the projectile is zero.


26. Horizontal motion with constant velocity and vertical motion with constant acceleration is called projectile motion.

27. The ball A is dropped from the top of a building simultaneously the ball B is thrown horizontally then the ball A will strike earlier than the ball B.

28. If a particle is moving with constant speed along a circle than its motion is uniform circular motion.

29. The angle subtended by a particle with the centre of the circle when it is moving from one point to another on its circumference is called angular velocity.

30. The unit of angular shift is radian.

31. The angular shift power unit time of the particle is called its angular velocity.

32. The direction of angular velocity of a particle can be determined by right hand rule.

33. If a particle covers equal angular displacement in equal intervals of time then its angular velocity is uniform.

34. The rate of change of angular velocity is called angular acceleration.

35. The velocity of the particle tangent to its circular path is called angular velocity.

36. In circular motion the time period and angular velocity of a particle are inversely proportional to each other.

37. If a particle is moving with constant speed along the circumference of a circle then the acceleration produced in it is called centripetal acceleration.

38. The direction of centripetal acceleration will always be towards the centre of the circle.

39. Centripetal force is also called the centre seeking force.

40. The tangential component of acceleration arises when the speed of the particle is changed.

41. In circular motion the centripetal component of acceleration arises when the speed of the object is constant.

42. Centripetal and tangential acceleration are always perpendicular to each other.

43. When an object moves round the circular track, the centripetal force is provided by frictional force.