If the distance travelled by a particle is non-zero, then its velocity cannot be
a) positive b) negative
c) infinity d) zero
Answers
Answer:
49. Gases possess more intermolecular space. It has less force of attraction and a
tendency of filling the entire part of the container by taking the shape of the
container.
50. * Motion repeated in equal intervals of time is called periodic motion. *. Earth
rotates itself at every 24hours (i.e) in equal intervals of time.
51. i. linear motion. -. Escalator ii. Curvilinear motion. -.
Throwing a ball iii. Circular motion. -. Merry go round
52. *. Force can change the state of the body from rest to motion or motion to rest.
*. It can either change the speed or direction or both.
*. It can change the shape of the body.
53. A rubber ball changes its shape on pressing but it is a solid.
This happens because when pressure is applied on the ball it makes it to change
the shape and gains its original shape when it is released.
XII.ANSWER IN DETAIL:
54. Any object which changes its position with or without application of force is called
motion.
Types of motion:
LINEAR MOTION:
Movement of an object in a straight line. Ex. Free falling object.
ROTATORY MOTION:
Movement of a body about its own axis. Ex. Rotating top
CIRCULAR MOTION:
Movement of a body in a circular path. Ex. Swirling of stone tied to a rope.
OSCILLATORY MOTION:
To and fro movement of an object. Ex. Pendulum
CURVILINEAR MOTION:
Movement of an object in a linear path but changes its direction. Ex. Throwing a
ball.
55. * Robots can handle dangerous materials and explore distant planets.
*. It can handle delicate objects and perform eye operations guided by human
surgeon.
*. It can target cancer cells and destroy them without harming healthy cells.
*. Nanobots are equipped to perform blood stream surgical procedures.