Hypothetical: If a 500-pound object falls off a cliff...?

Let's say we have an adult male (about 25-35 years old) of above average but not extreme strength. He is standing near a cliff. Now let's say a 500-pound object falls off that cliff, and he dives to catch it, landing with most of his body on solid ground (i.e., all except his head and one arm). Will he successfully stop the object's fall, or will he be pulled down into the void?