Work done = change in energy
E_1 = (1/2)*m*v_1^2
E_2 = (1/2)*m*v_2^2
E_2 - E_1 = (1/2)*m (v_2^2 - v_1^2)
m = 19.7" kg", v_1 = 2m//s, v2 = 4 m//s
E_2 - E_1 = (1/2)*19.7(4^2 - 2^2)
E_2 - E_1 = (1/2)*19.7(16 - 4)
E_2 - E_1 = (1/2)xx19.7xx12
E_2 - E_1 = 6xx19.7
E_2 - E_1 = 118.2 " Joules"