(a) A child slides down a water slide at an amusement park from an initial height h. The slide can be considered frictionless because of the water fl owing down it. Can the equation for conservation of mechanical energy be used on the child? (b) Is the mass of the child a factor in determining his speed at the bottom of the slide? (c) The child drops straight down rather than following the curved ramp of the slide. In which case will he be traveling faster at ground level? (d) If friction is present, how would the conservation-of-energy equation be modifi ed? (e) Find the maximum speed of the child when the slide is frictionless if the initial height of the slide is 12.0 m.

Physics 2 for Engineering Week 9 Magnetic Field and Forces B – Magnetic field FB– Magnetic force Moving charge q ge1erates a magnetic field B, which exerts F on anBther moving charge q 2 FB= q v x B With charge q, velocity v, magnetic field generated B, and magnetic force exerted F B Unit of B is Tesla (T); 1 Tesla = 1 N/Am = 10 Gauss FBis perpendicular to both v and B Motion of charged particles in magnetic field 2 FBis a centripetal force; FB= q v B = m v R Radius of orbit R = m v / q B where v is perpendicular to B Time Period = 2 π R / v; Angular velocity ω = v / R = q B / m Dots = vector pointing out of plane; crosses = pointing into plane In