Question

A packet is released from a balloon ascending vertically with a speed of 20m/s. The packet reaches the ground in 16 seconds. Find the height of the balloon at the time when the packet was released.(g =9.8m/s2)

Answer 1

Answer:

This is little bit tricky. Before answering i would quote a situation .

Suppose u are going in a bus. Anyhow u take a jump in a bus which is travelling at the speed of 60 m/s . So if I would ask u where would you land . What would be your answer?Think over it. It would improve the concept of relative velocity.

You would say, it would land somewhere other position and not on your original position (assuming that you have not understood relative velocity concept). But it is totally wrong. U should practically do it and get experience from this. It's totally BIZZARE. Isn't it. BECAUSE WHILE U ARE IN AIR, BUS MUST GO AHEAD ,SO U SHOULD FALL BACKWARD. SO WHY WE DO NOT FALL BACKWARD.

The reason is this while u are jumping ,u have two velocities upward and forward . Forward velocity is due to the fact that frame of reference is bus which is moving so u should have acquired this velocity. The same case is with objects on earth.

Basically the question demands that how u are aware of relative velocity concept.

So in this case, stone has initial velocity -14 m/s because reference frame is balloon. -ve sisgn shows that it goes opposite to the direction of velocity of balloon.Be aware of reference frame or frame of reference.

So it time can be calculated by equation of motion

V=U+gt

t=V-U/g

Here

But we have to calculate the value of V which can be found out with equation of motion

V^2-(-U)^2=2gS

Here we get V=46.43m/s

So time t=46.43+14/10= 6.43 seconds

Hope it will make u understand.