Q1. A uniform solid ball rolls smoothly along a floor, then up a ramp inclined at 20.4o. It momentarily stops while it has rolled 2.30 m along the ramp. What was its initial speed?

Q2. Two rays travelling parallel to the principal axis strike a large plano-convex lens. If the convex face is spherical, a ray near the edge does not pass through the focal point (spherical aberration occurs). Imagine this face has a radius of curvature of 24.0 cm and the two rays are at distances h1 = 0.500 cm and h2 = 13.0 cm from the principal axis. The lens has a refractive index of 1.30. Find out the difference Δx in the positions where each crosses the principal axis.