Rest and Motion Class-7th Goyal Brothers Physics Solutions Chapter-2. We Provide Step by Step Answers of Objective, True False , Fill in the blanks, Match the following , Short/Long Answer Type of Chapter-2, Force and Pressure: Motion Unit-1(Rest and Motion- Kinds of Motion) Visit official Website  for detail information about ICSE Board Class-7.

## Rest and Motion Class-7th Goyal Brothers

Physics Solutions Ch-2 (unit-1)

 Board ICSE Class 7th Subject Physics Book Name Goyal Brothers Theme-2 Force and Pressure: Motion Unit-1 Rest and Motion- Kinds of Motion Topic Solution of exercise questions Session 2023-24

### OBJECTIVE TYPE QUESTIONS

#### A. Fill in the blanks :

1. The motion described by a freely failing stone is _rectilinear_ motion.
2. The motion described by a spinning top is _rotatory_ motion.
3. A power drill making a hole in a wooden piece describe rotatory and _translatory_ motion.
4. A needle of a sewing machine describes _oscillatory_ motion.
5. A string of a sitar on being plucked describes _vibratory_ motion.

#### B. Statement given below are incorrect. write the correct correct statement:

1. An aeroplane flying toward north describes a periodic motion.

Correct Statement: An aeroplane flying toward north describes a non periodic motion.

2. A stone thrown upward at an angle describes rectilinear motion.

Correct Statement: A stone thrown upward at an angle describes curvilinear motion.

3. A person sitting in moving train is at rest with respect to surroundings outside the train.

Correct Statement: A person sitting in moving train is at motion with respect to surroundings outside the train.

4. The skin of a drum on hammering produces oscillatory motion.

Correct Statement: The skin of a drum on hammering produces vibratory motion.

5. A hockey player running up and down in the hockey ground describes a periodic motion.

Correct Statement: A hockey player running up and down in the hockey ground describes a oscillatory motion.

#### C. Write ‘True’ or ‘False’ for the following statements :

1. A ball thrown upward at ana angle describes curvilinear motion. [T]
2. A moving on a straight road describes rotatory motion. [F]
3. The earth revolving around its own axis describes linear ,motion. [F]
4. A freely suspended pendulum oscillating about its mean position performs vibratory motion. [F]
5. The weight of a body is not a constant quantity. [T]

#### 1. When a power drill bores a hole in a piece of wood, it describes :

(a) rotatory motion

(b) translatory motion

(c) curvilinear motion

(d) rotatory and translatory motion

Ans: (d) rotatory and translatory motion

#### 2. The motion describes by the sitting of violin is :

(a) oscillatory motion

(b) Vibratory motion

(c) Rectilinear motion

(d) curvilinear motion

Ans: (b) Vibratory motion

#### 3. The motion of a swing is  :

(a) curvilinear motion

(b) periodic motion

(c) rotatory motion

(d) Rectilinear motion

Ans: (a) curvilinear motion

#### 4. A spinning wheel describes a :

(a) curvilinear motion

(b) periodic motion

(c) rotatory motion

(d) translatory motion

Ans: (c) rotatory motion

#### 5. An aeroplane flying straight at a speed of 200 km/h describes :

(a) circulatory motion

(b) curvilinear motion

(c) Rectilinear motion

(d) periodic motion

Ans: (c) Rectilinear motion

#### Column B

1. When the position of a body does not change with respect to surroundings or time. 1. Circulatory motion
2. A motion which repeats itself after a fixed interval of time. 2. Vibratory motion
3. A kind of motion in which the moving object undergoes a change in size or shape. 3. Rotatory motion
4. A motion describes by a car on a circular road. 4. Rest
5. A motion describes by a table fan. 5. Periodic motion

 Column A Column B 1. When the position of a body does not change with respect to surroundings or time. 4. Rest 2. A motion which repeats itself after a fixed interval of time. 5. Periodic motion 3. A kind of motion in which the moving object undergoes a change in size or shape. 2. Vibratory motion 4. A motion describes by a car on a circular road. 1. Circulatory motion 5. A motion describes by a table fan. 3. Rotatory motion

STUDY QUESTIONS

#### Question 1. Define (a) rest (b) motion. Give an example in each case.

Answer: When the position of a body concerning its surroundings does not change with time, it is said to be “at rest”. For example, a house, a tree etc.

Motion is a change in position of an object over time. Motion is described in terms of displacement, distance, velocity. Examples area a book falling off a table, water flowing from the tap etc.

#### Question 2. By giving two examples define :

(a) Rectilinear motion : The motion of a body in a straight line is known as rectilinear motion. It is also known as translational motion. For example, A man/car moving on the straight road, a ball dropped from a height, a train running on the straight track will trace rectilinear path.

(b) Curvilinear motion: When an object moves along a curved path, then it is said to be undergoing a curvilinear motion. A car taking a turn is an example of curvilinear motion.

(c) Rotatory motion: A body is said to be in rotatory motion if it moves about a fixed axis. A spinning wheel is an example of rotatory motion. It moves in a circular path about a fixed axis. Similarly, the rotating fan is another example of rotatory motion.

(d) Circulatory motion: Circulatory motion is the movement of the body in a circular path when the speed remain constant but there is continuous direction of the motion of the object, Rotation of of moon around the earth is the example of uniform circular motion.

#### Question 3. By giving two examples define :

(a) Oscillatory motion: A type of motion in which a particle moves to and fro about a fixed point is called oscillatory motion.

Example: Pendulum Clock. The Pendulum in a pendulum clock makes to and fro movement, Freely hanging bob, Swing in the park etc.

(b) Vibratory motion: A type of motion in which a particle vibrates about a fixed point is called vibratory motion.

Example: The vibration of the phone when it rings, A tuning fork set to vibrate etc.

(c) Periodic motion : A repetitive motion which repeats itself after a regular interval of time is called the Periodic motion.

Example: by a rocking chair, a bouncing ball etc.

(d) Non-Periodic motion: Any motion which does not repeat itself after a regular interval of time is known as non-periodic motion.

Example : Occurrence of Earth quake , eruption of volcano etc

#### Question 4. Give an example when a body performs rotatory as well as translatory motion.

Answer: When a wheel moves at the plane surface, it exhibits translation as well as rotational motion at the same time.

#### Question 5. State the kind of motion described by the following :

(a) A train moving along a curved track – Curvilinear motion.

(b) A carrom coin moving over the carrom board – Rectilinear motion.

(c) A potter’s wheel –  Rotatory motion

(d) A pendulum of a wall clock – Oscillatory motion

(e) The skin of a drum – Vibratory motion.

(f) The motion of the heart of a resting person –  Periodic motion.

(g) A cricket ball rolling down the ground gradually slows down and finally stops – Non-periodic motion

— : end of Measurement of Density and Speed Class-7th Goyal Brothers :–-