Question

mission we4: mechanical energy
suppose an object moves downward at a constant speed. in this situation, the objects kinetic energy would __, its potential energy would , and its total mechanical energy would __. enter the three letters in their respective order.
a. remain the same
b. decrease
c. increase
d. ... nonsense! it is impossible to tell without additional info.

Explanation:

Step1: Analyze kinetic energy

Kinetic energy formula is \(K = \frac{1}{2}mv^{2}\). Since the object moves at a constant speed \(v\) and mass \(m\) is constant, kinetic energy remains the same.

Step2: Analyze potential energy

Gravitational potential energy formula is \(U = mgh\). As the object moves downward, height \(h\) decreases. With \(m\) and \(g\) constant, potential energy decreases.

Step3: Analyze total mechanical energy

Total mechanical energy \(E=K + U\). \(K\) remains the same (\(a\)), \(U\) decreases (\(b\)), so \(E\) decreases (\(b\)).

Answer:

a, b, b