Sign of gravity in free fall | Motion in a straight line | Physics | Khan Academy

[@Akintokun]

What decides the direction you take as positive

[@OpladduOp]

The direction you want throw if opposite - upward SMILALERY opposite😮

[@davidatlee2498]

Like the man said, it's tradition! We take down to be negative because the negative y-axis points down on a graph. If you flip ALL the signs of positions, velocities, and accelerations in a freefall problem, you will get consistent answers with the correct falling times and such. It's then your job to realize that a positive velocity means moving down. That said, I don't recommend this, because it's likely to confuse both you and your teacher.

[@Roshan-t4i2c]

Thank you 👍🏼😊

[@Fateymaa]

Conclusion: Sign of gravity in free fall has no significance. It just shows represents which direction the mass is moving. Right?

[@davidatlee2498]

No, this is exactly the wrong interpretation. Gravity always points down, regardless of which way the mass is moving. We traditionally take down to have a negative sign, so gravity is usually taken to be negative. The velocity of the mass may be positive (going up) or negative (going down) without affecting the direction of gravity. The alternative would be quite surprising. You don't expect that gravity pulls upward on a ball so long as it's moving upward, after all.

[@crazyr8496]

Sir if we have a question that acceleration is always _______ for free falling body . What would be the answer A positive B negative C zero D none

[@skypinkeducationyt]

negative

[@dramabuggy_8488]

Why ??? Negative

[@skypinkeducationyt]

@@dramabuggy_8488 because acceleration always happens in the direction of force and earth apply force in backward direction in free fall

[@crazyr8496]

@@dramabuggy_8488 any vector whose direction is opposite to direction of initial velocity has -ve sign

[@dramabuggy_8488]

Of we drop ball from building so it's a free fall so here acceleration is positive bcz velocity inc and acceleration downward so positive ..am I right??

[@pankajnaik7535]

Confusing

[@swastikmishra4770]

🥇1st