Question 18 (1 point)
A student walks downstairs to class. Which statement correctly describes the types of energy the student has at the top of the stairs and as she walks down the stairs?
a
kinetic energy at the top of the stairs; kinetic energy as she walks down
b
kinetic energy at the top of the stairs; potential energy as she walks down
c
potential energy at the top of the stairs; potential energy as she walks down
d
potential energy at the top of the stairs; kinetic energy as she walks down
d
potential energy at the top of the stairs; kinetic energy as she walks down
The correct answer is:
b) kinetic energy at the top of the stairs; potential energy as she walks down
To determine the correct statement describing the types of energy the student has at the top of the stairs and as she walks down, we need to understand the concepts of kinetic energy and potential energy.
Kinetic energy is the energy an object possesses due to its motion. It depends on the object's mass and velocity.
Potential energy is the energy stored in an object due to its position or state. It can be gravitational potential energy if it depends on the height or position of the object in a gravitational field.
In this scenario, when the student is at the top of the stairs and not moving, she has potential energy due to her position above the ground. This potential energy is gravitational potential energy. As she walks down the stairs, her potential energy decreases because she is lowering her position.
At the same time, the student also has kinetic energy as she is walking down the stairs. The student's motion contributes to her kinetic energy, which increases as her velocity increases.
Based on this understanding, the statement that correctly describes the types of energy the student has at the top of the stairs and as she walks down is:
d) potential energy at the top of the stairs; kinetic energy as she walks down.