Periodic Test 1 — Motion
Science
General Instructions:
Read the instructions carefully and strictly follow them:
- All questions are compulsory. Section D has an internal choice.
- Section A carries 1 mark per question, Section B 2 marks, Section C 3 marks and Section D 5 marks.
- Section E is a case-based question with three parts.
- Show every step of working in numerical questions.
Section A
(6 Marks)
- (1)A body moves along a circular path of radius $r$. What is its displacement after one complete revolution?
- A)$2\pi r$
- B)$\pi r$
- C)Zero
- D)
- (1)The slope of a distance–time graph gives the
- A)acceleration
- B)speed
- C)displacement
- D)distance
- (1)A car speeds up uniformly from 18 km/h to 36 km/h in 5 s. Its acceleration is
- A)1 m/s²
- B)2 m/s²
- C)3.6 m/s²
- D)5 m/s²
- (1)The area under a velocity–time graph gives the
- A)acceleration
- B)displacement
- C)speed
- D)time taken
- (1)The SI unit of acceleration is ______.
- (1)Assertion (A): An object moving along a circular path at a constant speed is accelerated.Reason (R): The direction of its motion changes at every point.
- A)Both A and R are true, and R is the correct explanation of A.
- B)Both A and R are true, but R is not the correct explanation of A.
- C)A is true, but R is false.
- D)A is false, but R is true.
Section B
(4 Marks)
- (2)Distinguish between distance and displacement, with one example.
- (2)A bus travels 120 km in 2 hours and then 60 km in the next hour. Find its average speed for the whole journey.
(Numerical answer)
Section C
(6 Marks)
- (3)A train starting from rest reaches a velocity of 72 km/h in 5 minutes. Assuming uniform acceleration, find (a) the acceleration and (b) the distance travelled in this time.
(Numerical answer)
- (3)Write the three equations of uniformly accelerated motion and say what each symbol stands for.
Section D
(5 Marks)
- (1 × 5 = 5)Using a velocity–time graph for an object moving with uniform acceleration, derive (a) $v = u + at$ and (b) $s = ut + \tfrac{1}{2}at^2$.
OR
A car moving at 20 m/s applies its brakes and stops in 4 s with uniform retardation. Find (a) the retardation, (b) the distance it travels before stopping, and (c) sketch its velocity–time graph, showing how the graph gives this distance.
Section E
(4 Marks)
- (4)
Read the passage and answer the questions.
A metro train starts from rest at a station and reaches 72 km/h in 40 s. It runs at this speed for 2 minutes, then slows down uniformly and comes to rest at the next station in 20 s.- (1)What is the train's acceleration in the first 40 s?
(Numerical answer)
- (1)How far does the train travel while it runs at a constant speed?
(Numerical answer)
- (2)Find the retardation while the train is stopping, and the distance it covers in that time.
(Numerical answer)