AReality said:

haha.. was eating nasi lemak... didn't really think & clicked move backward...

:embrass:

:embrass:

AReality said:

Take the unit mass of the air w.r.t vacuum space at positive.

Car accelerates.

The mass of air inside does not want to move. But,

the interior-back of the car pushes the air forward.

Since the car is accelerating, the force will always be there.

The air at the back is compressed, the air at the front is vacuumed.

Thus, there will always be a difference in pressure between the front and back of the balloon.

balloon moves forward due to difference in presure.

What about balloon inertia?

The unit mass of the balloon(with helium) w.r.t vacuum space is less than the mass of the air. Thus, the unit mass of the balloon w.r.t air is negative.

Heh... It's been a long time since I did physics...

Am I correct? Correct me if i'm wrong.

Car accelerates.

The mass of air inside does not want to move. But,

the interior-back of the car pushes the air forward.

Since the car is accelerating, the force will always be there.

The air at the back is compressed, the air at the front is vacuumed.

Thus, there will always be a difference in pressure between the front and back of the balloon.

balloon moves forward due to difference in presure.

What about balloon inertia?

The unit mass of the balloon(with helium) w.r.t vacuum space is less than the mass of the air. Thus, the unit mass of the balloon w.r.t air is negative.

Heh... It's been a long time since I did physics...

Am I correct? Correct me if i'm wrong.

In exam, we only accept the 1st answer. So no matter how hard you try, the 1st answer counts .