I- a circus star of mass 75.0 kg is to launched from
groundlevel by a spring loaded device so that she clears a wall
3.00 mhigh and 4.00m away and lands onthe ground 5.00m behind
thewall.
what is the minimum impulse the spring must deliver to
achievethe desired trajectory?

The minimum impulse the spring must give the circus star in order to clear the wall height and land on the ground again is 287.25Ns. The spring needs to provide an impulse sufficient at leather get the circus performer to the highest point in flight after which she is now in free fall under the control of gravity.

Explanation:

The step by step solution for this problem can be found in the attachment below. Thank you.

An  atom  (ours, not carroll's) consists of a positively charged  nucleus, surrounded by one or more negatively charged particles called  electrons. the positive charges equal the negative charges, so the atom has no overall charge; it is electrically neutral. most of an atom's mass is in its nucleus; the mass of an electron is only 1/1836 the mass of the lightest nucleus, that of hydrogen. although the nucleus is heavy, it is quite small compared with the overall size of an atom. the radius of a typical atom is around 0.1 to 0.25 nanometres (nm), whereas the radius of a nucleus is about 10-6  nm.  *  if an atom were enlarged to the size of the earth, its nucleus would be only 200 feet in diameter and could easily rest inside a small football stadium.read more on -

Amicroscope, because these cells are so small that you would not be able to see them, or what they attack without it.