from a balloon rising vertically upwards at 5m/s a stone is thrown up ...
Analysis of the Situation
The given situation involves a balloon rising vertically upwards at a velocity of 5m/s. At the same time, a stone is thrown up with a velocity of 10m/s relative to the balloon. We need to find the velocity of the stone with respect to the ground after 2 seconds.
Velocity of Balloon with Respect to Ground
Before we can find the velocity of the stone with respect to the ground, we need to find the velocity of the balloon with respect to the ground. Since the balloon is rising vertically upwards, its velocity with respect to the ground is simply 5m/s.
Velocity of Stone with Respect to Balloon
Next, we need to find the velocity of the stone with respect to the balloon. Since the stone is thrown up with a velocity of 10m/s relative to the balloon, its velocity with respect to the balloon is 10m/s upward.
Velocity of Stone with Respect to Ground
To find the velocity of the stone with respect to the ground, we need to add the velocity of the stone with respect to the balloon to the velocity of the balloon with respect to the ground. This gives us:
Velocity of stone with respect to ground = Velocity of balloon with respect to ground + Velocity of stone with respect to balloon
Plugging in the values, we get:
Velocity of stone with respect to ground = 5m/s + 10m/s = 15m/s
Conclusion
Therefore, the velocity of the stone with respect to the ground after 2 seconds is 15m/s.