6. A 70 kg pole-vaulter converts the kinetic energy, of running at ground level, into
potential energy to clear the crossbar at a height of 4 m above the gound. What is the
minimum velocity that he must have had at takeoff (while on the ground) to clear the bar
(minimum would be when velocity at the top was zero - you could still be moving
forward at the top, but this would require more velocity at the beginning)?

In triangle △abc, ∠abc=90°, bh is an altitude. find the missing lengths. ah=4 and hc=1, find bh.

Harry the hook has 7 1/3 pounds of cookie dough.she uses 3/5 of it to bake cookie. how much cookie dough does she use to make cookie?

Anew test for ra is being developed. the test is administered to 750 patients with ra and 750 without ra. for the sake of the question, assume the prevalence of ra in this population is 50%. of the 750 patients with ra, 575 have a positive result. of the 750 patients without ra, 150 have a positive result. what is the positive predictive value of the new test? a575/(575+150) b. 600/(600+ 150) c. 575/(575+125) d. 600/(600+ 125)