The discussion revolves around a physics problem involving impulse, specifically a car changing its speed and direction. The original poster presents a scenario where a car with a mass of 100 kg transitions from moving at 25 m/s in the X-direction to 20 m/s in the Y-direction, seeking to calculate the impulse.
The discussion is active, with participants exploring different interpretations of the problem statement. Some provide guidance on understanding the sequential nature of the velocities, while others express differing views on the initial conditions and the implications for calculating impulse.
There is a lack of clarity regarding the initial conditions of the car's motion, as well as the interpretation of the phrase "and then" in the problem statement, which affects how participants approach the calculation of impulse.
Why the minus sign?mailmas said:The Attempt at a Solution
I = 100(20 (j) - 25(i))[/B]
Because these are before and after velocities.rude man said:Why the minus sign?
mailmas said:and then
Oh yes? I interpreted the problem as starting from zero velocity and ending with 25 i + 20 j. The change is just that.haruspex said:Because these are before and after velocities.
You are still ignoring the "and then". These are sequential circumstances.rude man said:Oh yes? I interpreted the problem as starting from zero velocity and ending with 25 i + 20 j. The change is just that.