a boy standing on top of a building throws a stone to hit an object on the ground. state the energy changes that occur in this event.
I don't even know it, that's why I asked the question, pls if u know it pls tell me. thanks.
Lacking significant data. Need to know height of building. Also, if he "throws" it, need to know power of his throw.
The potential energy goes down by an amount m g h where m is ball mass, g is gravity acceleration and h is the height of the pitchers hand above ground.
The pitch is thrown with horizontal speed u and vertical speed v.
The kinetic energy due to the horizontal speed (1/2) m u^2 remains constant until ground except for air friction.
However v is tricky because it might be initially upward if the horizontal distance needed is large. I f so (1/2) m v^2 will decrease and mgh will increase until the ball stops rising at the top and falls, increasing v as it falls. Then by the bottom m g h = 1/2 m v^2, the final kinetic energy due to v is equal to the original m g h. The kinetic energy due to horizontal speed u never changed during the trip except for warming the air a little.
Pls help me out of this problem
In this scenario, there are several energy changes that occur during the process of a boy throwing a stone from the top of a building to hit an object on the ground. Let's break it down:
1. Potential Energy (Gravitational Energy): Initially, when the stone is held by the boy on top of the building, it possesses potential energy due to its height from the ground. The higher the building, the more potential energy it has.
2. Kinetic Energy: When the boy releases the stone, it starts accelerating downwards due to the force of gravity. As it falls, its potential energy is converted into kinetic energy, which is the energy of motion. This kinetic energy increases as the stone gains speed on its way down.
3. Air Resistance: As the stone moves through the air, it encounters air resistance. Air resistance is a force opposing motion caused by friction between the stone and the air molecules. This force acts in the opposite direction to the stone's velocity, resulting in a loss of kinetic energy. Some of the stone's energy is converted into heat and sound due to air resistance.
4. Impact Energy: As the stone reaches the ground and hits the object, its remaining kinetic energy is transferred to the object upon impact. This energy causes the object to move or undergo deformation, depending on its characteristics.
Overall, the energy changes in this event involve the transformation of potential energy into kinetic energy, as well as the conversion of some kinetic energy into heat and sound due to air resistance, and the transfer of the remaining kinetic energy upon impact with the object on the ground.