Kinematics

Written by Dr. Hamza Farooq (Physics)

Class 9 · Physics · 10 questions

Name: ____________________ Date: ____________

Which of these is a vector quantity?
- A Time
- B Velocity
- C Speed
- D Distance
A car covers 120 km in 2 hours. What is its average speed?
- A 120 km/h
- B 60 km/h
- C 240 km/h
- D 40 km/h
A body starts from rest and reaches 20 m/s in 5 s. What is its acceleration?
- A 2 m/s²
- B 5 m/s²
- C 100 m/s²
- D 4 m/s²
The slope of a distance-time graph gives:
- A Acceleration
- B Force
- C Speed
- D Displacement
An object falls freely from rest for 3 s. What is its speed at the end? (g = 10 m/s²)
- A 90 m/s
- B 30 m/s
- C 10 m/s
- D 20 m/s
The area under a speed-time graph gives:
- A Distance travelled
- B Force
- C Time
- D Acceleration
A car moves with a constant speed of 20 m/s. How far does it travel in 5 s?
- A 200 m
- B 100 m
- C 4 m
- D 25 m
Which equation of motion links v, u, a and t?
- A v = u a t
- B s = v t
- C a = v + u
- D v = u + a t
A body moving with uniform velocity has an acceleration of:
- A 9.8 m/s²
- B Zero
- C Infinite
- D 1 m/s²
A stone is thrown upwards. At its highest point its velocity is:
- A Negative infinity
- B Zero
- C Equal to g
- D Maximum

Answer key

1. B, 2. B, 3. D, 4. C, 5. B, 6. A, 7. B, 8. D, 9. B, 10. B

Velocity has both magnitude and direction. Speed, distance and time have only magnitude.
Average speed = distance / time = 120 / 2 = 60 km/h.
a = (v - u) / t = (20 - 0) / 5 = 4 m/s².
On a distance-time graph, slope = change in distance / change in time, which is speed.
v = g t = 10 x 3 = 30 m/s.
Area under a speed-time graph equals the distance travelled.
Distance = speed x time = 20 x 5 = 100 m.
The first equation of motion is v = u + a t.
Uniform velocity means no change in velocity.
It momentarily stops before falling.