# Samacheer Kalvi 7th Science Term 1 Unit 2 Solutions

## Samacheer Kalvi 7th Science Term 1 Unit 2 Book Back Question and Answers/Solutions:

Samacheer Kalvi Class 7th Std Science Book Back 1 Mark and 2 Mark Question & Answers PDF uploaded and available below. Class 7th Standard New Syllabus 2022 to 2023 Book Back Question & Answer solutions available for both English and Tamil Medium. Class 7 New Science Book Term 1 Unit 2 – Force and Motion Answers/Solutions Guide are provided on this page. 7th Std Science Book is of 1st Term consists of 7 units, 2nd and 3rd Term consists of 6 units. All Units/Chapters of Term 1st, 2nd, 3rd Science Book Back One, and Two Mark Solutions are given below.

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### Samacheer Kalvi 7th Science Book Back Chapter 2 Term 1 Answers/Solutions Guide PDF:

7th Science Subject 1 Mark and 2 Mark Solutions Guide PDF available below. Click the Download option to download the book back 1 Mark & 2 Mark questions and answers. Take the printout and use it for exam purposes.

### Force and Motion

I. Choose the appropriate answer :

1. A particle is moving in a circular path of radius r. The displacement after half a circle would be
(a) Zero
(b) R
(c) 2r
(d) r/2
(c) 2r

2. Which of the following figures represent uniform motion of a moving object correctly?  3. Suppose a boy is enjoying a ride on a merry go round which is moving with a constant speed of 10 m/s. It implies that the boy is.
(a) at rest
(b) moving with no acceleration
(c) in accelerated motion
(d) moving with uniform velocity
(c) in accelerated motion

4. From the given v-t graph it can be inferred that the object is (a) in uniform motion Time
(b) at rest
(c) in non uniform motion
(d) moving with uniform acceleration
(d) moving with uniform acceleration

5. How can we increase the stability of an object?
(a) lower the centre of gravity
(b) raise the centre of gravity
(c) increase the height of the object
(d) shorten the base of the object
(a) lower the centre of gravity

II. Fill in the blanks :

1. The shortest distance between the two places is _______
2. The rate of change of velocity is _______
3. If the velocity of an object increases with respect to time, then the object is said to be in _______ acceleration.
4. The slope of the speed-time graph gives _______
5. In _______ equilibrium its centre of gravity remains at the same height when it is displacement

1. displacement
2. acceleration
3. positive
4. velocity
5. neutral

III. Match the following :

 1 Displacement (a) Knot 2 Light travels through vacuum (b) Geometric centre 3 Speed of ship (c) Metre 4 Centre of gravity of the geometrical shaped object (d) Larger base area 5 Stability (e) Uniform velocity

1 – c; 2 – e; 3 – a; 4 -d; 5 – b

IV. Analogy:

1. velocity : metre/ second :: acceleration : _______
metre/second2

2. length of scale : metre : : speed of aeroplane : _______
knot

3. displacement / time : velocity : : speed / time : _______
acceleration

1. All objects having uniform speed need not have uniform velocity. Describe with the help of examples.
An object moving in uniform circular motion is moving around the perimeter of the circle with a constant speed. While the speed of object is constant, its velocity is changing, Ex: Merry-go-round, roller coaster, planets orbiting the sun.

2. “She moves at a constant speed in a constant direction”. Rephrase the same sentence in fewer words using concepts related to motion.
She moves in a straight line with constant velocity.

3. Correct your friend who says “The acceleration gives the idea of how fast the position changes”.
Velocity gives an idea of how fast the position changes, or Acceleration gives an idea of how fast the velocity changes.

1. Show the shape of the distance – time graph for the motion in the following cases.
a. A bus moving with a constant speed
b. A car parked on a road side.
(a) A bus moving with constant speed.

(b) A car parked on road side

2. Distinguish between speed and velocity. 3. What do you mean by constant acceleration?