M1 question

I was looking at the solutions for a question and I saw that the velocity is given a minus. Is this because the object is falling down?

Oh and if a object is thrown upwards from 10m of the ground, the displacement would be -10 right???


Posted from TSR Mobile

The velocity is most likely minus as it is going in the opposite direction you considered positive e.g Taking upwards as positive and ending up with the object falling downwards would give negative velocity

If you are saying the object then ends up on the ground then yes at the end it is -10

so if its going upwards U is positive and went its coming down V would be negative?


Posted from TSR Mobile

so if its going upwards U is positive and went its coming down V would be negative?


Posted from TSR Mobile

U and V are two velocities at different times, this does not dictate whether you put a minus or not. By convention, you take upwards as the positive direction therefore any object moving upwards would have its velocity as $+k$ ms^-1 and any objecting moving down would have a velocity of $-m$ ms^-1.

If you throw an object upwards, and it travels a maximum height of 10m, then the displacement is +10m AT that height. If that object falls into a hole in the ground that is 6m deep, then the displacement would be -6m. The displacement is the vector by which an object has been displaced, ie moved away from the starting position.