Motion and Time — Class 7 Science NCERT Solutions (Free)

Free step-by-step NCERT solutions for Class 7 Science chapter "Motion and Time" — 8 important questions with detailed answers for CBSE board exam preparation.

TL;DR: Free step-by-step NCERT solutions for Class 7 Science chapter "Motion and Time" — 8 important questions with detailed answers for CBSE board exam prep…

By Syllab.in · Updated Jun 14, 2026

Key Questions Covered:

Define motion. Give examples of motion and rest.
Calculate speed if distance = 150 km and time = 3 hours.
A car travels 200 m in 10 seconds. Calculate its speed in m/s and km/h.
What is the difference between speed and velocity?
What is acceleration? Give examples.
A bus accelerates from rest to 30 m/s in 10 seconds. Calculate acceleration.
+ 2 more questions in the full chapter

Solutions Summary:

Question	Status
Define motion. Give examples of motion and rest.	✓ Solved
Calculate speed if distance = 150 km and time = 3 hours.	✓ Solved
A car travels 200 m in 10 seconds. Calculate its speed in…	✓ Solved
What is the difference between speed and velocity?	✓ Solved
What is acceleration? Give examples.	✓ Solved
A bus accelerates from rest to 30 m/s in 10 seconds. Calc…	✓ Solved

Showing 6 of 8 questions

Q1: Define motion. Give examples of motion and rest.

Motion: change in position of an object with respect to a reference point over time. Examples of motion: car moving on road, bird flying, falling ball. Examples of rest: book on table, person sitting on chair, building. Note: Motion and rest are relative - depend on reference point chosen.

Q2: Calculate speed if distance = 150 km and time = 3 hours.

Step 1: Formula = Speed = Distance / Time Step 2: Speed = 150 km / 3 h Step 3: Speed = 50 km/h Answer: Speed is 50 km per hour.

Q3: A car travels 200 m in 10 seconds. Calculate its speed in m/s and km/h.

Step 1: Speed = Distance / Time = 200 m / 10 s = 20 m/s Step 2: Convert m/s to km/h: Multiply by 3.6 (or 18/5) Step 3: 20 m/s × 3.6 = 72 km/h Answer: Speed = 20 m/s = 72 km/h

Q4: What is the difference between speed and velocity?

Speed: distance traveled per unit time; scalar quantity (only magnitude); always positive. Velocity: displacement per unit time; vector quantity (magnitude + direction); can be positive or negative. Example: 60 km/h is speed; 60 km/h north is velocity. Formula: Speed = Distance/Time; Velocity = Displacement/Time

Q5: What is acceleration? Give examples.

Acceleration: rate of change of velocity with time. It measures how quickly an object speeds up, slows down, or changes direction. Formula: a = (v - u) / t where v = final velocity, u = initial velocity, t = time. Examples: Car increasing speed (positive acceleration), car braking (negative acceleration/deceleration), circular motion (change in direction).

Q6: A bus accelerates from rest to 30 m/s in 10 seconds. Calculate acceleration.

Step 1: Initial velocity u = 0 m/s (starts from rest) Step 2: Final velocity v = 30 m/s, Time t = 10 s Step 3: Acceleration a = (v - u) / t = (30 - 0) / 10 Step 4: a = 30 / 10 = 3 m/s² Answer: Acceleration = 3 m/s²

Showing 6 of 8 questions. Visit the full page for complete solutions.