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# Physics help watch

1. When an object is released from a rising hot air balloon, it is said to acquire the hot air balloon's velocity. I don't understand why. Wouldn't an object that is dropped from a hot air balloon simply begin to fall down immediately? Please can somebody explain this to me, with a diagram preferably so that I can visually understand what's going on. Thanks
2. PLZ
3. It's hard to explain this. The object will gain the velocity of the hot air balloon but you feel that object will just fall down immediately. This feeling is because the velocity of the hot air balloon is rather low.

For example, the balloon is rising with a velocity = 5 m/s. So initially, the velocity of the object is u = 5 m/s. We have acceleration due to gravity a = -9.81 m/s^2 (negative since I have set the upward direction to be positive). So we want to find the time t when the object starts to fall down. This is when the object has reached its highest point and its velocity v = 0. We have t = (v-u)/a = (0-5)/(-9.81) = 0.509 s.

So barely half a second after release the object starts falling down so this is probably why you feel that the object just falls down immediately.

This is actually rather similar when you drop a object out of a moving car, except that the object will gain horizontal velocity and there is no horizontal acceleration. This causes the object to continue to move forward even after it has been dropped out of the car.

Hope this helps. Just pm me if you are still unclear

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Updated: November 11, 2017
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