Ahorizontal wheel rotates at 4.66 rev/s. for a point 0.4 m from the center
of the wheel,
(a) the speed in m/s
(b) the centripetal acceleration?

Explanation:

For this we will need the circumference of the cirkel the point makes. We know that it is located at 0.4 m from the center so r=0.4. In case you didn't you can use 2×pi×r to find the circumference of a cirkel. so plugging r=0.4 we get 4/5pi meters. In one second the wheels spins 4.66 times, a point on that wheel would cover 4.66×(4/5pi)=11.711... meters each second. So 11.711m/s