NCERT Class VII Science Solutions: Chapter 13-Motion and Time Part 3

Download PDF of This Page (Size: 195K)

VERY SHORT ANSWER QUESTIONS

Question 10:

A simple pendulum is oscillating between two points A and B as shown in Figure. Is the motion of the bob uniform or non - uniform?

As showing in images is a A simple pendulum is oscillating between two points

A Simple Pendulum is Oscillating between Two Points

As showing in images is a A simple pendulum is oscillating between two points

Answer:

The motion of bob is non – uniform, as it does not cover equal intervals of time.

Question 11:

Paheli and Boojho have to cover different distances to reach their school but they take the same time to reach the school. What can you say about their speed?

Answer:

They do not have equal speed because they cover unequal distances in equal intervals of time. One of them has higher speed, whom has to cover larger distance with respect to other.

Question 12:

If Boojho covers a certain distance in one hour and Paheli covers the same distance in two hours, who travels in a higher speed?

Answer:

Boojho moves at a higher speed as he covers the same distance in a lesser time than Paheli.

SHORT ANSWER QUESTIONS

Question 13:

Complete the data of the table given below with the help of the distance-time graph given in Figure

Distance-Time Graph (Q)
distance-time graph (Q)

Distance

(m)

0

4

?

12

?

20

Time

(s)

0

2

4

?

8

10

As showing in images is a distance-time graph of the motion is uniform

Distance-Time Graph of the Motion is Uniform

As showing in images is a distance-time graph of the motion is uniform

Answer:

Distance-Time Graph (A)
distance-time graph (A)

Distance

(m)

0

4

8

12

16

20

Time

(s)

0

2

4

6

8

10

Question 14:

The average age of children of Class VII is 12 years and 3 months. Express this age in seconds.

Answer:

12 years 3 months