Frame of Reference - UNSOLVED PRACTICE SET
Chapter: Kinematics | Topic: Frame of Reference
FRAME OF REFERENCE - UNSOLVED PRACTICE SET
Topic: Frame of Reference
Multiple Choice Questions
Q1. A passenger sitting in a moving bus is at rest with respect to:
- The road outside
- The bus itself
- A tree on the roadside
- A car overtaking the bus
Q2. Which of the following is NOT a characteristic of an inertial frame of reference?
- Newton's laws of motion are valid in it
- It is either at rest or moving with uniform velocity
- It is accelerating with respect to another inertial frame
- A body not acted upon by any force remains at rest or in uniform motion
Q3. Two cars are moving in the same direction with the same velocity. A passenger in one car will observe the other car to be:
- Moving forward rapidly
- Moving backward
- At rest
- Moving in a circular path
Q4. The Earth can be considered approximately as an inertial frame of reference for:
- Studying the motion of electrons inside an atom
- Studying the motion of satellites and everyday objects
- Studying the motion of galaxies far away
- None of the above, as Earth is never an inertial frame
Q5. A frame of reference attached to a freely falling elevator is:
- An inertial frame
- A non-inertial frame
- Sometimes inertial and sometimes non-inertial
- Neither inertial nor non-inertial
Q6. The concept that motion is relative was first clearly articulated by:
- Aristotle
- Galileo Galilei
- Isaac Newton
- Albert Einstein
Short Answer Questions
Q7. Define a frame of reference. Explain why the description of motion depends on the choice of frame of reference.
Q8. Distinguish between an inertial frame of reference and a non-inertial frame of reference. Give one example of each.
Q9. A student sitting in a classroom is at rest with respect to the Earth. Is the student at rest or in motion with respect to the Sun? Explain your answer.
Q10. In a school bus moving at constant speed on a straight road, a student drops a pen from his hand. Describe the path of the pen as seen by:
(a) The student himself
(b) A person standing on the roadside
Q11. Why is a frame of reference attached to the Earth considered approximately inertial for most practical purposes, even though the Earth is rotating and revolving?
Q12. Two trains are moving on parallel tracks in opposite directions with the same speed. A passenger in Train A throws a ball vertically upward. Describe the path of the ball as observed by:
(a) The passenger in Train A
(b) A passenger in Train B
Long Answer Questions
Q13. Explain the concept of a frame of reference with examples. Discuss the importance of choosing an appropriate frame of reference when analysing motion. Why is the ground often taken as the standard frame of reference in everyday situations?
Q14. Describe Galileo's principle of relativity. How does it relate to the concept of inertial frames? Discuss why the laws of physics appear the same in all inertial frames of reference.
Q15. A cricket ball is hit by a batsman in a moving train. Analyse the motion of the ball from three different frames of reference:
(i) The frame attached to the batsman
(ii) The frame attached to the train
(iii) The frame attached to the ground
Discuss how the description of the ball's velocity and path differs in each frame.
Application-Based Problems
Q16. A boat is moving eastward with a velocity of 5 m/s with respect to the river water. The river is flowing northward with a velocity of 3 m/s with respect to the ground.
(a) Choose an appropriate frame of reference and draw a vector diagram showing the velocities.
(b) Calculate the velocity of the boat with respect to the ground.
(c) Calculate the direction in which the boat actually moves with respect to the east direction.
Q17. In the Delhi Metro, a train is moving at a constant speed of 20 m/s. A passenger walks from the rear end to the front end of the train at a speed of 1.5 m/s relative to the train.
(a) What is the passenger's velocity with respect to the platform?
(b) If another passenger walks from the front to the rear at 1.5 m/s relative to the train, what is his velocity with respect to the platform?
(c) What do these observations tell you about the relativity of motion?
Q18. A helicopter is flying horizontally at a constant height of 500 m with a speed of 50 m/s. At a certain instant, it drops a food packet for flood relief.
(a) Describe the path of the packet as seen from the helicopter (frame attached to the helicopter).
(b) Describe the path of the packet as seen from the ground.
(c) Calculate the horizontal distance from the point of release to where the packet hits the ground.
(d) Explain why the two observers describe different paths for the same packet.