Special relativity cannot be used to study an object in which frame of reference

The question is incomplete. The complete question is:

Special relativity cannot be used to study an object in which frame of reference?

A. A frame of reference that has no change in velocity

B. A frame of reference that is moving in a circle

C. A frame of reference that has a constant, positive acceleration

D. A frame of reference that has a constant, negative acceleration

A frame of reference that has a constant, positive acceleration

A frame of reference that has a constant, negative acceleration

Explanation:

Special relativity applies to frames of reference in which an object is moving at constant velocity.

If the velocity is constant, it implies that acceleration will be zero hence options C and D will be correct since they both involve a non-zero change in velocity.

here we know that ball will drop down by total distance 3.2 m

so here we know that

now using kinematics

now in the same time it will cover horizontal distance of 0.75 m

so speed of the ball will be

f=ma newton

f=100x2.5=250n