Final answer:
The correct option is c. The example of potential energy from the provided options is a slinky at the top of the stairs. Potential energy is the energy held by an object's position or state, such as height above ground.
Step-by-step explanation:
The example of potential energy in the list provided is (c) A slinky at the top of stairs. Potential energy is stored energy that has the capacity to do work, which is dependent on its position or state. A slinky positioned at the top of the stairs possesses gravitational potential energy because of its height above the ground. The moment it is released, that potential energy is converted into kinetic energy as it moves down the stairs.
Answering the follow-up questions:
- The gravitational potential energy (GPE) of an object is given by the formula GPE = mgh, where m is mass, g is the acceleration due to gravity, and h is the height. For a ball at the top of a 15-meter hill, GPE would be calculated using its mass (which needs to be provided) multiplied by 9.8 m/s2 (value of g on Earth) and the height of 15 m.
- To find the velocity of the ball when it hits the ground, you can use the conservation of energy principle or kinematics equations. Under the conservation of energy, all the potential energy converts into kinetic energy as it reaches the bottom, assuming no friction. The formula ½ mv2 = mgh can be used, where v is the velocity and the other symbols are the same as before. You would solve for v to find the velocity at the bottom.
- For a bullet shot upwards with a muzzle velocity, you would again use the principle of conservation of mechanical energy. The potential energy at its highest point would be equal to the kinetic energy it had when it left the muzzle. So, ½ mv2 = mgh can be used to solve for h, with v equal to the muzzle velocity of 200 m/s and the mass of the bullet as 50 g (converted to kg for the calculation).