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A person sitting in an open car moving at constant velocity throws a ball vertically upwards in air. If effect of air resistance is neglected, the ball will fall
Explanation
When a person in a car moving at a constant velocity throws a ball vertically upwards, the ball possesses the same horizontal velocity as the car due to inertia [t2]. According to the principles of projectile motion, horizontal and vertical components of motion are independent [t1]. Since air resistance is neglected, there is no horizontal force to change the ball's horizontal speed [t1]. Consequently, both the car and the ball cover the same horizontal distance in the same amount of time [c4][t2]. From the perspective of an observer in the car (an inertial reference frame), the ball appears to move only vertically [t4]. From an outside observer's perspective, the ball follows a parabolic trajectory but maintains the car's horizontal speed [t4]. Therefore, the ball will land exactly back in the hands of the person [t2][t4].
Sources
- [1] Science-Class VII . NCERT(Revised ed 2025) > Chapter 8: Measurement of Time and Motion > 8.4 Uniform and Non-uniform Linear Motion > p. 117