At a place where an object is thrown vertically downward with a speed of while a different object is thrown vertically upward with a speed of which object undergoes a greater change in speed in a time of 2 s?

Both objects will undergo the same change in velocity

Explanation:

m = Mass of the Earth =  5.972 × 10²⁴ kg

G = Gravitational constant = 6.67 × 10⁻¹¹ m³/kgs²

r = Radius of Earth = 6371000 m

m = Mass of object

Any object which is falling has only the acceleration due to gravity.

The acceleration due to gravity on Earth is 9.81364 m/s²

So, the speeds of the objects will change at an equal rate of 9.81364 m/s² but the change will be negative when an object is thrown up.

Hence, both objects will undergo the same change in velocity.

there are no contact forces mentioned on the list of choices that you've provided.