Kinetic energy is the energy of a moving object.
Kinetic energy can be calculated using the following equation;
K.E = [tex] \frac{1}{2} m v^{2} [/tex]
where - m - mass of object
v - speed of object
substituting the values in the equation
K.E = 1/2 x 21 kg x (1 m/s)²
K.E = 10.5 J