Answer:
The ping pong ball, the light molecules have greater speed
Explanation:
The kinetic energy of an object is defined as
[tex]K=\frac{1}{2}mv^2[/tex]
where
m is the mass of the object
v is its speed
It follows that the speed can be written as
[tex]v=\sqrt{\frac{2K}{m}}[/tex]
In this problem, both the golf ball and the ping pong ball have kinetic energy K. However, the mass of a gold ball is larger (approx. 45 g) than that of a ping pong ball (approx. 4 g): therefore, since v is inversely proportional to the square root of the mass, it follows that the ping pong ball must have a greater speed in order to achieve the same kinetic energy of the golf ball.
The same argument can be applied to the gaseous mixture: if there are more massive molecules and light molecules, and if they all have the same kinetic energy, then this means that the light molecules must have a greater speed, as a result again of the equation
[tex]v=\sqrt{\frac{2K}{m}}[/tex]
