10 questions · Form 4 Mathematics Bab 7: Graphs of Motion
A car's motion is graphed on a speed-time graph. Section A has a gradient of 3, Section B has a gradient of 0, and Section C has a gradient of -5. Rank the magnitude of acceleration/deceleration from highest to lowest.
Prefer reading to quizzing? All 10 questions are listed below with the answer and explanation under each one.
1. A car's motion is graphed on a speed-time graph. Section A has a gradient of 3, Section B has a gradient of 0, and Section C has a gradient of -5. Rank the magnitude of acceleration/deceleration from highest to lowest.
Answer: B
Magnitude of gradient: Section C is |-5| = 5 m/s², Section A is |3| = 3 m/s², Section B is 0 m/s². Highest magnitude is C > A > B.
2. If an object has an initial speed of u m/s and comes to rest after t seconds with acceleration a, which equation represents the relationship?
Answer: B
Final speed v = 0. Acceleration a = v - ut = 0 - ut = -ut.
3. What does a horizontal line on a speed-time graph signify?
Answer: B
A horizontal line on a speed-time graph means the speed remains constant over time (zero acceleration).
4. Convert a speed of 72 km/h into m/s.
Answer: B
72 km/h = 72 × 1000 m3600 s = 720003600 = 20 m/s.
5. A horizontal line on a distance-time graph means that the object is:
Answer: C
A horizontal line on a distance-time graph means distance is constant as time passes, so speed is 0 and the object is stationary.
6. If the gradient of a speed-time graph is zero during a 12-second interval, what is the acceleration during that time?
Answer: C
Gradient of speed-time graph represents acceleration. Zero gradient means zero acceleration.
7. A car travels 150 km in 2.5 hours. What is its average speed in km/h?
Answer: B
Average Speed = Total Distance / Total Time = 150 km / 2.5 h = 60 km/h.
8. What physical quantity does the area under a speed-time graph represent?
Answer: C
The area enclosed under a speed-time graph and the time axis equals the total distance traveled.
9. What is the formula for calculating average speed from a distance-time graph?
Answer: B
By definition, Average Speed is always calculated as Total Distance Covered divided by Total Time Taken.
10. What does a negative gradient on a speed-time graph indicate?
Answer: A
A negative gradient on a speed-time graph indicates that speed is decreasing over time, which is deceleration.