Practice Reference Frame in Physics
Use these practice problems to test your method after reviewing the concept explanation and worked examples.
Quick Recap
A coordinate system attached to a particular observer that is used to describe the positions and motions of objects.
Are you 'moving' on a train? Depends on whether you ask someone on the train or the platform.
Showing a random 20 of 50 problems.
Example 1
mediumIn the ground frame, ball A moves east at and ball B moves north at . Find the speed of A in B's frame.
Example 2
hardAn elevator accelerates upward at . In the elevator frame, what is the apparent gravitational acceleration? Use .
Example 3
easyThe same passenger, viewed from the platform, when the train moves at m/s. Her velocity?
Example 4
easyAn escalator moves up at . A man walks down the escalator at relative to the escalator. What is his velocity in the ground frame?
Example 5
easyName a non-inertial reference frame you experience in everyday life.
Example 6
hardA river is wide flowing east at . A boat can move at in still water. What heading angle (measured from due north) achieves zero downstream drift, and what is the crossing time?
Example 7
hardAn observer in an accelerating bus (acceleration forward) sees a ball on a frictionless tray. In the bus frame, what is the ball's apparent acceleration?
Example 8
mediumCar A moves m/s east, car B moves m/s west. Find A's velocity relative to B.
Example 9
hardPlane A flies east, plane B flies at north of east. Find the speed of B in A's frame.
Example 10
easyTwo cars drive side by side at m/s. What is one car's velocity relative to the other?
Example 11
easyCan an object be at rest in one frame and moving in another at the same time?
Example 12
mediumIn the ground frame a falling raindrop moves straight down at . A car moves east at . In the car frame, what angle do the streaks on the side window make with the vertical?
Example 13
mediumA coin is dropped inside a car moving east at at constant velocity. In the ground frame, what is the coin's horizontal velocity while falling?
Example 14
easyTrain A moves east at and Train B moves east at , both relative to the ground. What is the velocity of Train A relative to Train B?
Example 15
challengeA boat heads m/s north across a river flowing m/s east. Find the boat's speed relative to the bank.
Example 16
mediumIf frame S' moves at constant velocity relative to frame S, is S' inertial when S is inertial?
Example 17
mediumA river flows m/s east. A swimmer's velocity is m/s east relative to water. Find the swimmer's velocity relative to the bank.
Example 18
challengeStanding on a train moving m/s east, you throw a ball m/s east (train frame) and it lands. In the ground frame, what is the ball's horizontal velocity?
Example 19
mediumA person walks m/s toward the front of a train moving m/s. Find their velocity relative to the ground.
Example 20
mediumA boy throws a ball horizontally at from a flatbed truck moving at in the same direction. What is the ball's initial horizontal speed in the ground frame?