Question

A pitcher throws a baseball towards home plate. The baseball, which has a mass of 142 g, approaches the plate with 128 J of kinetic energy.
Calculate the speed of the baseball.

Answer 1

Mass=142g
K.E=128 J
Speed or Velocity=?
K.E=1/2*m*v^2
128=1/2*142*v^2
128=72*v^2
v^2=128/72
v^2=1.777
by taking square rt 
v= 1.333ms-1
so the speed will be 1.333 ms-1