Question

as the block slides down the ramp, what happens to its kinetic energy k, potential energy u, and total mechanical energy e?
○ k decreases;u increases;e stays the same
○ k decreases;u increases;e increases
○ k increases;u increases;e increases
○ k increases;u decreases;e stays the same

Explanation:

1. Kinetic Energy (K): As the block slides down the ramp, its speed increases (assuming no significant friction for mechanical energy conservation). Kinetic energy is given by \( K = \frac{1}{2}mv^2 \), so with increasing speed (\( v \)), \( K \) increases.
2. Potential Energy (U): Gravitational potential energy is \( U = mgh \), where \( h \) is the height above a reference point. As the block slides down, \( h \) decreases, so \( U \) decreases.
3. Total Mechanical Energy (E): In the absence of non - conservative forces (like friction, which is often assumed in basic energy problems for ramps), mechanical energy is conserved. So \( E=K + U \) stays the same.

Looking at the options, the one that matches \( K \) increases, \( U \) decreases, and \( E \) stays the same is the last option.

Answer:

K increases; U decreases; E stays the same (the last option in the given choices)