i have an answer but i am not sure if it's correct..

You are a pirate working for Dread Pirate

Roberts. You are in charge of a cannon that

exerts a force 20000 N on a cannon ball while

the ball is in the barrel of the cannon. The

length of the cannon barrel is 2.18 m and

the cannon is aimed at a 33◦

angle from the

ground.

The acceleration of gravity is 9.8 m/s

2

.

If Dread Pirate Roberts tells you he wants

the ball to leave the cannon with speed v0 =

71 m/s, what mass cannon ball must you use?

Answer in units of kg

and

a person wearing frictionless inline skates is pushed with a force of 47 N, how far must be pushed starting from rest to get to have 352 J of KE?