1)
Need to consider force calculations
When you go in circular motion, there's a centripetal acceleration
of mv^2/r required. When cyclist is at the very top, the only
forces providing this acceleration is his weight and any reaction
force from the track.
To just remain in contact, reaction force = 0
Hence, mv^2/r = mg
and v = sqrt(gr) at the top
Supposed he did not add more power when he is on that circular
track, we need to take into account KE loss due to increase in
PE
so loss in KE = 1/2mV^2 - 1/2mv^2 = mg(6), V = entry speed
V^2 = v^2 + 12g = 15g
V = sqrt(15g) m/s
I think....
