A steel cable lifting a heavy box stretches by ΔL . In order for the cable to stretch by only half of ΔL , by about what factor must its diameter increase? 1.4 4.0 2.0 0.25 0.50

Determine the fraction of the magnitude of kinetic energy lost by a neutron (m1 = 1.01 u) when it collides head-on and elastically with a target particle at rest which is 21h (heavy hydrogen, m = 2.01 u).