# CBSE NCERT Solutions for Class 7 Science Chapter 13

The students can download and practice these NCERT science solutions for class 7 from the links provided in the below article. These solutions are prepared by our subject experts in such a way that the students understand all the topics covered in the syllabus of class 7 science quite effectively.

CBSE NCERT Solutions for Class 7 Science Chapter 13:

Question-1:

A car moves with a speed of 40 km/h for 15 minutes and then with a speed of 60
km/h for the next 15 minutes. The total distance covered by the car is:
(i) 100 km (ii) 25 km
(iii) 15 km (iv) 10 km

Solution:

(ii) 25 km
Firstly, the car is moving with 40 km/hr for 15 minutes.
15 minutes =15/60 hrs = 1/4 hr
Distance covered = 40 × 1/4 = 10 km
Secondly, the car is moving with 60 km/hr for 15 minutes.
Distance covered = 60 × 1/4 = 15km
Total distance covered = 10 km + 15 km = 25 km

Question-2:

Classify the following as motion along a straight line, circular or oscillatory
motion:
(i) Motion of your hands while running.
(ii) Motion of a horse pulling a cart on a straight road.
(iii) Motion of a child in a merry-go-round.
(iv) Motion of a child on a see-saw.
(v) Motion of the hammer of an electric bell.
(vi) Motion of a train on a straight bridge.

Solution:

(i) Oscillatory motion
(ii)Straight line motion
(iii)Circular motion
(iv) Oscillatory motion
(v)Oscillatory motion
(vi) Straight line motion

Question-3:

A simple pendulum takes 32 s to complete 20 oscillations. What is the time
period of the pendulum?

Solution:

Numbers of oscillations = 20
Time taken = 32 sec
Time period of the pendulum = Time taken/ Number of Oscillations = 32/20 = 1.6 s.