Question

A helicopter ascending upawards throws a stone downwards. Is the displacement or velocity of the stone negative?

Answer 1

see below

Explanation:

it depends by the velocity with which the stone is throwed. If you let the stone go down is the same that you trrows the stone upwards with the same velocity of the helicopter and it will go up till it will loss it kinetic energy and then it will fall down.

Otherwise if you call Vt the velocity of throw and Vh the velocity of helicopter, g the gravity aceleration, and you have positive the direction upwards you will have
`V_(tot) = V_h - V_t - g xx t` and
`s = s°+ V_h xx t - V_t xx t -1/2 at^2`
and the value of velocity and of displacement will be positive or negative in according with the value of the two velocity and il will be always negative after few seconds