A. Answer the following questions:
1. When is a body said to be at rest?
2. When is a body said to be in motion?
3. Explain translatory motion. What is the name given to a translatory motion along a straight path?
4. What is rotatory motion? Give some examples.
5. What is meant by circular motion?
6. When is a body said to be in vibratory motion? Give an example.
7. When does a body have an oscillatory motion? Give an example.
Answers
1.A body is said to be at rest if it does not change its position with respect to its immediate surroundings.
2.A body is said to be in motion when its position continuously changes with respect to time.
3.When an object in translatory motion moves along a straight line, it is said to be in rectilinear motion.
4.A few examples of the rotatory motion are as follows: The motion of the earth about its own axis around the sun is an example of rotary motion. While driving a car, the motion of wheels and the steering wheel about its own axis is an example of rotatory motion.
5.circular motion is a movement of an object along the circumference of a circle or rotation along a circular path. ... The rotation around a fixed axis of a three-dimensional body involves circular motion of its parts.
6.When a part of the body remains fixed and the rest part moves to and fro, that is called vibratory motion. For example: when humans breathe, their chest expands and contracts.
7.Oscillatory motion is defined as the to and fro motion of an object from its mean position. The ideal condition is that the object can be in oscillatory motion forever in the absence of friction but in the real world, this is not possible and the object has to settle into equilibrium.