# 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.