All Flashcards

What is the effect of doing positive work on an object?

The object's kinetic energy increases.

What is the effect of doing negative work on an object?

The object's kinetic energy decreases.

What happens when a spring is compressed or stretched?

Elastic potential energy is stored in the spring.

What happens when non-conservative forces are present in a system?

Mechanical energy is not conserved; some energy is converted to thermal energy.

What happens to gravitational potential energy as an object falls?

Gravitational potential energy decreases, and kinetic energy increases (assuming no non-conservative forces).

How is kinetic energy derived from work?

Start with Work: $W = Fd$ 2. Newton's Second Law: $F = ma$ 3. Kinematics: $v_f^2 = v_i^2 + 2ad$ which can be rearranged to $a = \frac{v_f^2 - v_i^2}{2d}$ 4. Substitute: $W = mad = m(\frac{v_f^2 - v_i^2}{2d})d = \frac{1}{2}mv_f^2 - \frac{1}{2}mv_i^2 = ΔK$

What are the steps to derive kinetic energy from work?

Start with Work: $W = Fd$ 2. Newton's Second Law: $F = ma$ 3. Kinematics: $v_f^2 = v_i^2 + 2ad$ which can be rearranged to $a = rac{v_f^2 - v_i^2}{2d}$ 4. Substitute: $W = mad = m( rac{v_f^2 - v_i^2}{2d})d = rac{1}{2}mv_f^2 - rac{1}{2}mv_i^2 = ΔK$