Q1. A 5.00--long ladder has mass 12.5 kg and is leaning against a frictionless wall, making a 64 degree angle with the horizontal. If the coefficient of friction between the ladder and ground is 0.42, what is the mass of the heaviest person who can safely ascend to the top of ladder?
Q2. A shell is fired from the ground with an initial speed of 1.70*10^3 m/s at an initial angle of 55° to the horizontal.
(a) Neglect air resistance; find the shell's horizontal range.
(b) Find the amount of time shell is in motion.