Which one of the following statement is wrong?

A body of mass 0.5 kg travels in a straight line with velocity \(v = ax^{3 / 2 }\) where \(a = 5 m^{- 1 / 2} s^{- 1}\). What is the work done by the net force during its displacement from x = 0 to x = 2 m?
1. 50 J

2. 45 J

3. 68 J

4. 90 J

A 1 kg block situated on a rough incline is connected to a spring of spring constant $100<mspace\; width="1em"></mspace>N<mspace\; width="1em"></mspace>m^{-1}$ as shown in the figure. The block is released from rest with the spring in the unstretched position. The block moves 10 cm down the incline before coming to rest. The coefficient of friction between the block and the incline is:

(Assume that the spring has a negligible mass and the pulley is frictionless.)

1. 0.03
2. 0.14
3. 0.11
4. 0.08