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Questions and Answers
How long does it take for the bird to cross the train?
How long does it take for the bird to cross the train?
What is the relative speed of the two trains when they cross each other?
What is the relative speed of the two trains when they cross each other?
What speed must the scooterist maintain to overtake the bus in 100 seconds?
What speed must the scooterist maintain to overtake the bus in 100 seconds?
If both trains are 100m long, how long will it take for them to completely cross each other?
If both trains are 100m long, how long will it take for them to completely cross each other?
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What is the speed of the train moving north?
What is the speed of the train moving north?
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What is the velocity of Pinki represented in the coordinate system?
What is the velocity of Pinki represented in the coordinate system?
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What does the notation $v_{AP} = (-6, 0°)$ indicate?
What does the notation $v_{AP} = (-6, 0°)$ indicate?
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If $v_{PR} = (6, 70°)$, what does the angle represent?
If $v_{PR} = (6, 70°)$, what does the angle represent?
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How is the relationship between $v_{PR}$ and $v_{RP}$ defined?
How is the relationship between $v_{PR}$ and $v_{RP}$ defined?
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What is the significance of the negative sign in $x_{PR} = -x_{RP}$?
What is the significance of the negative sign in $x_{PR} = -x_{RP}$?
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What is the formula for calculating relative velocity between two objects A and B?
What is the formula for calculating relative velocity between two objects A and B?
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In Case 1, what is the calculated relative velocity $V_{AB}$ between objects A and B?
In Case 1, what is the calculated relative velocity $V_{AB}$ between objects A and B?
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What is the result of the relative velocity $V_{AB}$ in Case 3?
What is the result of the relative velocity $V_{AB}$ in Case 3?
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What is the resulting velocity when calculating $V_{AB}$ in Case 4?
What is the resulting velocity when calculating $V_{AB}$ in Case 4?
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How do you convert 54 km/hr to meters per second?
How do you convert 54 km/hr to meters per second?
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What is the relative speed of object A compared to object B?
What is the relative speed of object A compared to object B?
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If the velocity of object B is $2(10 - 5)$, what is its value?
If the velocity of object B is $2(10 - 5)$, what is its value?
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How does an observer perceive their own motion when viewing other objects?
How does an observer perceive their own motion when viewing other objects?
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What does a position-time graph illustrate?
What does a position-time graph illustrate?
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What is the significance of relative separation in motion analysis?
What is the significance of relative separation in motion analysis?
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What is the equation for the time when two objects meet again?
What is the equation for the time when two objects meet again?
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If Ramlal accelerates at $2 m/s^2$ from rest, what is his initial velocity?
If Ramlal accelerates at $2 m/s^2$ from rest, what is his initial velocity?
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What is the velocity of the bus in the scenario described?
What is the velocity of the bus in the scenario described?
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What distance does the bus cover when Ramlal catches up?
What distance does the bus cover when Ramlal catches up?
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What is the solution for the time variable t from the equation $0 = t^2 + 21t - 100$?
What is the solution for the time variable t from the equation $0 = t^2 + 21t - 100$?
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What is the speed of the third car moving in the opposite direction?
What is the speed of the third car moving in the opposite direction?
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How far does each of the first two cars travel before the third car meets them?
How far does each of the first two cars travel before the third car meets them?
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What is the time taken by the third car to meet the first and second cars?
What is the time taken by the third car to meet the first and second cars?
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What is the minimum velocity required for the man to catch the bus after 5 seconds?
What is the minimum velocity required for the man to catch the bus after 5 seconds?
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How long does the bus accelerate to reach its speed of 10 m/s?
How long does the bus accelerate to reach its speed of 10 m/s?
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What is the formula for the time taken by Preeti to walk up a moving escalator?
What is the formula for the time taken by Preeti to walk up a moving escalator?
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If Preeti's speed on foot is represented by Vm and the speed of the escalator by Vs, what is the combined time taken on the escalator moving upwards?
If Preeti's speed on foot is represented by Vm and the speed of the escalator by Vs, what is the combined time taken on the escalator moving upwards?
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What is the relationship between the times t1 and t2 for Preeti walking and using the moving escalator?
What is the relationship between the times t1 and t2 for Preeti walking and using the moving escalator?
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According to the table of relative motion in medium under gravity, what is the speed of an object moving upwards after 1 second?
According to the table of relative motion in medium under gravity, what is the speed of an object moving upwards after 1 second?
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What does the notation VBA = 20m/s represent in the context of relative motion?
What does the notation VBA = 20m/s represent in the context of relative motion?
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What is the speed of the boat in still water?
What is the speed of the boat in still water?
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If a man is walking on a stationary escalator, how would you calculate the time taken to cover a distance S?
If a man is walking on a stationary escalator, how would you calculate the time taken to cover a distance S?
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What formula represents the time taken when a man is stationary on a moving escalator?
What formula represents the time taken when a man is stationary on a moving escalator?
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When a man is moving with the escalator, what is the correct expression for the time taken to cover distance S?
When a man is moving with the escalator, what is the correct expression for the time taken to cover distance S?
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How long did the boat take to travel downstream 30 km?
How long did the boat take to travel downstream 30 km?
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What type of motion does a ball exhibit when it is in free fall under the influence of gravity?
What type of motion does a ball exhibit when it is in free fall under the influence of gravity?
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What is the value of $V_{m/g}$ when a bus is at rest?
What is the value of $V_{m/g}$ when a bus is at rest?
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If a ball is dropped from a height of 80m, what happens to its velocity as it falls?
If a ball is dropped from a height of 80m, what happens to its velocity as it falls?
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When a man swims downstream in a moving river, what is the formula for his velocity relative to the ground?
When a man swims downstream in a moving river, what is the formula for his velocity relative to the ground?
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When a ball is thrown upwards with an initial speed of 50m/s, what will happen to its motion over time?
When a ball is thrown upwards with an initial speed of 50m/s, what will happen to its motion over time?
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What will $V_{m/g}$ equal if a man is swimming upstream in a river flowing at 40?
What will $V_{m/g}$ equal if a man is swimming upstream in a river flowing at 40?
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At what time do the two balls (one dropped from 80m and one thrown upwards) meet?
At what time do the two balls (one dropped from 80m and one thrown upwards) meet?
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If the bus is moving at 40 and the person inside is also moving at 40, what is the velocity of the person relative to the ground?
If the bus is moving at 40 and the person inside is also moving at 40, what is the velocity of the person relative to the ground?
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What type of problem does the scenario of two balls meeting emphasize in physics?
What type of problem does the scenario of two balls meeting emphasize in physics?
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What effect does the river's flow have when a man is not swimming?
What effect does the river's flow have when a man is not swimming?
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Study Notes
Relative Velocity in 2-D
- Relative velocity concepts include ( V_{AB} = V_A - V_B ) and ( x_{AB} = x_B - x_A ).
- Cases illustrate the computation of relative speeds under various scenarios.
- Conversion for speed: ( 54 \text{ km/hr} = 15 \text{ m/s} ).
Case Examples
- Problem 1: A train travels North at 10 m/s, a bird South at 5 m/s. The time for the bird to cross the train is 15 seconds.
- Problem 2: Two trains, each 100m long, moving parallel at 72 km/h and 36 km/h will take approximately 6.67 seconds to cross each other.
- Problem 3: A bus travels at 10 m/s; a scooterist aims to overtake it in 100 seconds. The required speed of the scooterist is 20 m/s.
Position-Time Graph and Comments
- Velocity comparison: ( V_{pa} = 10 - 5 = 5 \text{ m/s} ) and ( V_{pb} = 2(10 - 5) = 10 \text{ m/s} ).
Velocity and Relative Motion Problems
- Meeting Time Equation: To find when two objects meet, use ( t = 2u + \frac{1}{2}at^2 ).
- Ramlal's Catch-Up: For a bus moving at 1 m/s and Ramlal accelerating at 2 m/s², the equation ( ut + \frac{1}{2}at^2 = 100 + vt ) leads to finding non-negative time for catching up.
Relative Motion of Cars
- Two cars moving in the same direction with 30 km/h speeds, separated by 5 km, along with a third car moving opposite, yields the third car's speed as 60 km/h.
Minimum Velocity Calculation
- For a man catching a bus that accelerates from rest at 2 m/s² over 50m, required velocity to match the bus after 5 seconds is 10 m/s.
Moving Frames of Reference
- Situations illustrate how velocities transform in different frames, such as a moving bus, affecting observed speeds.
Motion in Water Scenarios
- A boat travels downstream 30 km in 3 hours, upstream in 5 hours, leading to a boat speed of 8 km/h in still water through derived equations.
Escalator Motion
- Three different scenarios for a man walking on an escalator demonstrate time calculations depending on whether the escalator is stationary or moving.
Motion Under Gravity
- In free fall, an object's motion is non-uniform due to variable acceleration instigated by gravity.
Ball Drop Problem
- A dropped ball from 80m meets an upward-thrown ball at approximately 3 seconds based on calculated values, demonstrating combined motion dynamics.
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Description
This quiz covers the concept of relative velocity in two dimensions, focusing on vector representation and directional components. Students will analyze velocities of different objects and their interactions. Ideal for physics students exploring kinematics.
