How much work must be done on a 10-kg snowboard to increase its speed from 4 ms to 6 ms 100 J.?

The work done on the snowboard is equal to the change in kinetic energy. The initial kinetic energy is (1/2)mv^2 = (1/2)(10 kg)(4 m/s)^2 = 80 J. The final kinetic energy is (1/2)(10 kg)(6 m/s)^2 = 180 J. Therefore, the work done is 180 J - 80 J = 100 J.