A 400 kg ice boat moves on runners on essentially frictionless ice.A steady wind blows,applying a constant force to the sail. At the end of 8.0 sec run,the acceleration is `0.5m/s^(2)`. (a) What was the acceleration at the beginning of the run? (b) What was the force due to the wind ? (c) What retarding force must be applied at the end of 4.0 sec to bring the ice boat to rest by the end of the next 4 sec ? (assume boat was at rest at time t = 0)

Answer

`[0.5 m//s^(2), 200 N, 400 N]`