what is the % change in kienetic energy if

a) speed is increased by 10%

b) momentum is increased by 20%

let the inital velocity be v and mass of the object be m

then 

a) final velocity of the ball becomes (v+10/100*v)= 1.1 v

then change in kinetic energy = [ 1/2*m*v_f ²- 1/2 *m*v_i² ]/ 1/2*m*v_i²  = 1.1²-1= .21 or 21 %

b) as the momentum is directly proportional to the velocity therefore and 20% increase in velocity only 

 final velocity of the ball becomes (v+20/100*v)= 1.2 v

then change in kinetic energy = [ 1/2*m*v_f ²- 1/2 *m*v_i² ]/ 1/2*m*v_i²  = 1.2²-1= .44 or 44 %