Understanding "Uniform Motion" and "Relative Speed" is crucial for students preparing for school and competitive exams. These concepts form the foundation of kinematics in physics and are frequently tested through MCQs and objective questions. Practicing these questions not only enhances conceptual clarity but also boosts your confidence, helping you score better in exams.
What You Will Practise Here
Definitions and characteristics of uniform motion
Understanding relative speed and its applications
Key formulas related to uniform motion and relative speed
Graphical representation of motion
Solving problems involving two or more moving objects
Conceptual questions that link theory with practical scenarios
Important questions that frequently appear in exams
Exam Relevance
The topics of uniform motion and relative speed are integral parts of the physics syllabus for CBSE, State Boards, NEET, and JEE. Students can expect questions that assess their understanding of motion concepts, often presented in the form of numerical problems or conceptual MCQs. Common question patterns include calculating speeds, determining distances, and analyzing motion graphs, making it essential to master these topics for effective exam preparation.
Common Mistakes Students Make
Confusing uniform motion with accelerated motion
Misunderstanding the concept of relative speed when multiple objects are involved
Neglecting to apply the correct formulas in problem-solving
Overlooking the significance of direction in relative speed calculations
Failing to interpret motion graphs accurately
FAQs
Question: What is uniform motion? Answer: Uniform motion refers to the motion of an object moving at a constant speed in a straight line.
Question: How do I calculate relative speed? Answer: Relative speed is calculated by adding or subtracting the speeds of two objects depending on their direction of motion.
Now is the time to enhance your understanding of these concepts! Dive into our practice MCQs and test your knowledge on Uniform Motion and Relative Speed. Every question you solve brings you one step closer to exam success!
Q. A boat can travel 30 km upstream in 2 hours. What is the speed of the current if the speed of the boat in still water is 15 km/h?
A.
2.5 km/h
B.
3 km/h
C.
3.5 km/h
D.
4 km/h
Solution
Speed upstream = Speed of boat - Speed of current. Speed upstream = 30 km / 2 h = 15 km/h. Therefore, 15 km/h - Speed of current = 15 km/h, so Speed of current = 0 km/h.
Q. A man walks at a speed of 4 km/h and runs at 8 km/h. If he walks for 30 minutes and then runs for 15 minutes, what is his average speed for the entire trip?
A.
5 km/h
B.
6 km/h
C.
7 km/h
D.
8 km/h
Solution
Total distance = (4 km/h × 0.5 h) + (8 km/h × 0.25 h) = 2 km + 2 km = 4 km. Total time = 0.5 h + 0.25 h = 0.75 h. Average speed = Total distance / Total time = 4 km / 0.75 h = 5.33 km/h.
Q. A man walks at a speed of 4 km/h and runs at a speed of 10 km/h. If he walks for 1 hour and then runs for 1 hour, what total distance does he cover?
A.
14 km
B.
15 km
C.
16 km
D.
17 km
Solution
Distance = Walking distance + Running distance = 4 km + 10 km = 14 km.
Q. A man walks at a speed of 4 km/h and runs at a speed of 12 km/h. If he walks for 1 hour and then runs for 1 hour, what total distance does he cover?
A.
16 km
B.
20 km
C.
24 km
D.
28 km
Solution
Distance = Walking distance + Running distance = 4 km + 12 km = 16 km.
Q. A person travels 30 km at a speed of 10 km/h and then 20 km at a speed of 5 km/h. What is the average speed for the entire journey?
A.
6 km/h
B.
7 km/h
C.
8 km/h
D.
9 km/h
Solution
Total distance = 30 km + 20 km = 50 km. Total time = (30/10) + (20/5) = 3 + 4 = 7 hours. Average speed = Total distance / Total time = 50 km / 7 h = 7.14 km/h.
Q. A person travels 60 km at a speed of 20 km/h and then 40 km at a speed of 40 km/h. What is the average speed for the entire journey?
A.
25 km/h
B.
30 km/h
C.
35 km/h
D.
40 km/h
Solution
Total time = (60/20) + (40/40) = 3 + 1 = 4 hours. Total distance = 60 + 40 = 100 km. Average speed = Total distance / Total time = 100 km / 4 h = 25 km/h.
Q. If two cars are moving in the same direction at speeds of 60 km/h and 80 km/h, how long will it take for the faster car to overtake the slower car if they start 100 km apart?
A.
1 hour
B.
1.5 hours
C.
2 hours
D.
2.5 hours
Solution
Relative speed = 80 km/h - 60 km/h = 20 km/h. Time = Distance / Speed = 100 km / 20 km/h = 5 hours.
Q. Two cars start from the same point and drive in opposite directions. Car A travels at 70 km/h and Car B at 90 km/h. How far apart will they be after 1 hour?
A.
160 km
B.
150 km
C.
140 km
D.
130 km
Solution
Distance apart = (Speed of A + Speed of B) × Time = (70 km/h + 90 km/h) × 1 h = 160 km.
