Question

a spaceship is traveling through space. suddenly, its kinetic energy decreases. what is most likely to be true about the speed of the spaceship?
the speed increases to make up for the decrease in kinetic energy.
the speed increases as the kinetic energy is converted into speed.
the speed remains the same because speed and kinetic energy are not related.
the speed decreases as the kinetic energy decreases.

Explanation:

The formula for kinetic energy is \( KE = \frac{1}{2}mv^2 \), where \( m \) is mass and \( v \) is speed. Mass of the spaceship is constant (assuming no mass loss). So, if kinetic energy (\( KE \)) decreases, and mass (\( m \)) is constant, the speed (\( v \)) must decrease because \( KE \) is directly related to the square of speed. The other options are incorrect: speed and KE are related, so the third option is wrong; an increase in speed would increase KE (not decrease it), so the first two options are wrong.

Answer:

D. The speed decreases as the kinetic energy decreases.