Basics & Definitions (Q1–Q8)
1
What is motion?
Change in position of an object with time relative to a reference point.
2
Define distance.
Total length of the path travelled; scalar quantity.
3
Define displacement.
Shortest straight-line from initial to final position with direction; a vector.
4
When can distance be equal to displacement?
When motion is along a straight line without changing direction.
5
Define speed.
Rate of change of distance with time; scalar (units: m/s).
6
Define velocity.
Rate of change of displacement with time; a vector (m/s).
7
What is acceleration?
Rate of change of velocity with time (m/s²).
8
What does negative acceleration indicate?
Velocity decreasing with time (deceleration/retardation) in chosen positive direction.
Types of Motion (Q9–Q13)
9
What is uniform motion?
Motion with constant speed (or constant velocity if direction fixed).
10
What is non-uniform motion?
Motion in which speed or velocity changes with time.
11
What is uniformly accelerated motion?
Motion with constant acceleration (same change in velocity per unit time).
12
Give an everyday example of uniform motion.
A car moving at constant speed on a straight highway (no acceleration).
13
Give an example of non-uniform motion.
A car accelerating from rest at a traffic signal.
Units & Conversions (Q14–Q17)
14
SI unit of speed/velocity?
Metre per second (m/s).
15
SI unit of acceleration?
Metre per second squared (m/s²).
16
Convert 90 km/h to m/s.
90 ÷ 3.6 = 25 m/s.
17
How to convert km/h to m/s?
Divide by 3.6 (multiply by 5/18).
Equations of Motion (Q18–Q25)
18
State the first equation of motion (uniform acceleration).
v = u + a t (v: final velocity, u: initial velocity, a: acceleration, t: time).
19
State the second equation of motion.
s = u t + ½ a t² (s: displacement in time t).
20
State the third equation of motion.
v² = u² + 2 a s (relates velocities, acceleration and displacement).
21
If u = 0, what does s = ut + ½ a t² reduce to?
s = ½ a t² (for motion from rest).
22
Which equation is used when time is not given?
v² = u² + 2 a s (no time variable required).
23
What is average velocity formula?
Average velocity = displacement / time interval.
24
What is average speed?
Total distance travelled divided by total time taken.
25
How is instantaneous velocity obtained from s–t graph?
Slope of tangent to the s–t curve at that instant gives instantaneous velocity.
Graphical Interpretation (Q26–Q30)
26
What does slope of s–t graph represent?
Speed (or velocity if s is displacement).
27
What does area under v–t graph represent?
Displacement (area between curve and time axis).
28
A horizontal line on v–t graph indicates what?
Constant velocity (zero acceleration).
29
A straight inclined line on v–t graph means?
Uniform acceleration (constant slope).
30
How to get displacement between t1 and t2 on v–t graph?
Calculate area under v–t curve from t1 to t2 (shapes: rectangle/triangle/trapezium).
Free Fall & Gravity (Q31–Q34)
31
What is free fall?
Motion under gravity alone (neglecting air resistance).
32
Standard acceleration due to gravity (g) approx.?
Approximately 9.8 m/s² (often approximated to 10 m/s² in problems).
33
Direction of acceleration for an object thrown upward?
Downward (−g if upward taken as positive), so it decelerates until momentary stop.
34
If an object is dropped from rest, what is its initial velocity?
Zero (u = 0).
Relative Motion (Q35–Q37)
35
Relative velocity of A w.r.t B formula?
vA/B = vA − vB (vector subtraction).
36
If two objects move in same direction, how to get relative speed?
Subtract their speeds (|vA − vB|).
37
If two objects move opposite directions, relative speed equals?
Sum of their speeds (vA + vB).
Problem Solving & Short Tricks (Q38–Q42)
38
When should you use v = u + at?
When initial velocity, acceleration and time are involved and final velocity is required.
39
When to use s = ut + ½at²?
When displacement during time t is required with known u and a.
40
Common unit error to check in problems?
Ensure time in seconds (convert minutes/hours) and speed in m/s (convert km/h).
41
How to choose sign convention?
Pick one direction as positive; keep it consistent throughout the solution.
42
Quick check after solving a kinematics problem?
Check units, sign of result, and whether magnitude is physically reasonable.
Short Numerical Answers & Concepts (Q43–Q48)
43
A car moves at 36 km/h. What is its speed in m/s?
36 ÷ 3.6 = 10 m/s.
44
If a = 2 m/s² and u = 3 m/s, what is v after 4 s?
v = u + at = 3 + 2×4 = 11 m/s.
45
If an object starts from rest and a = 5 m/s² for 2 s, distance covered?
s = ½ a t² = 0.5×5×4 = 10 m.
46
A ball thrown up with u = 20 m/s. Time to reach max height? (g = 10 m/s²)
v = 0 → t = (v−u)/a = (0−20)/(−10) = 2 s.
47
Maximum height reached by above ball?
v² = u² + 2as → 0 = 400 + 2(−10)s → s = 20 m.
48
If average velocity is zero does it mean object is at rest?
No — average zero can occur if displacement over interval is zero (e.g., round trip) though object may have moved.
Revision Reminders & Miscellaneous (Q49–Q50)
49
Why sketch diagrams or graphs in motion problems?
They visualise directions, initial/final positions and help choose correct equation/signs.
50
One-line tip to score in Motion questions in exams?
Use consistent sign convention, convert units, pick the equation containing knowns, and show units in the answer.