You use an inclined plane to move furniture into a truck. you perform 105 kj of work, but only do 88 kj of useful work. what is the efficiency of the inclined plane?

whichever one it is, it's definitely not one that you included on the list you provided.

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