Please explain to me step by step.

41. II A rifle shoots a 4.20 g bullet out of its barrel. The bullet has a muzzle velocity of 965 m/s just as it leaves the barrel. Assuming a constant horizontal acceleration over a distance of 45.0 cm start- ing from rest, with no friction between the bullet and the barrel, (a) what force does the rifle exert on the bullet while it is in the barrel? (b) Draw a free-body diagram of the bullet (i) while it is in the barrel and (ii) just after it has left the barrel. (c) How many g's of acceleration does the rifle give this bullet? (d) For how long a time is the bullet in the barrel?45. II BIO A standing vertical jump. NFL player Gerald Sensabaugh recorded a 46 inch standing vertical jump at the 2005 NFL Combine, at that time the highest for any NFL player in the his- tory of the Combine. Sensabaugh weighed about 200 1b when he set the record. (a) What was his speed as he left the floor? (b) If the jump motion took 0.300 s, what were the magnitude and direction of his acceleration (assuming it to be constant) while he was push- ing against the floor? (c) Draw a free-body diagram of Sensabaugh during the jump. (d) Use Newton's laws and the results of part (b) to calculate the normal force on his feet as he jumped