PRELAB QUESTIONS1.(Pendulum section) Suppose a pendulum bob is suspended from a pivot by a mass-less string of length l, measured to the center of the bob. a.Show that if I draw the pendulum back by an angle θ, the center of the bob is elevated by the distance: 2(1 cos ) 2 sin ( / 2)h ll = −=(58)b. Using the results of part (a), show that the speed of the pendulum bob at the bottom of its travel should be:2sin( / 2)vgl=(59)Hint: recall that 2(1 cos( )) / 2 sin ( / 2)−.2.(Ramp section) Suppose the height of the ramp is h1= 0.40m, and the foot of the ramp is horizontal, and is h2= 1.5m above the floor. What will be the horizontal distance traveled by the following four objects before they hit the floor? Assume that R= 15mm in each case; assume that the density of steel is 7.8 g/cm3; and assume that the density of aluminum is 2.7 g/cm3.a. A solid steel sphere slidingdown the ramp without friction. b.A solid steel sphere rollingdown the ramp without slipping. c.A spherical steel shell with shell thickness 1.0 mm rollingdown the ramp without slipping. d.A solid aluminum sphere rollingdown the ramp without slipping.