Please solve this tasks and explain with all details the solution, because I am preparing for the exam and there is a chance that I will have similiar tasks. Thank you in advance

Unless specied otherwise, assume g = 9.31 mils}. Problem 1 125 Hts! Energy; An 85kg roller coaster cart is traveling 4 mfs at the top of a hill 50 meters off the ground. How fast is it traveling at the top of a second hill 20 meters off the ground? Assume zero friction Problem 2 25 ts Force and Work A Skg block moves in a straight line on a horizontal frictionless surface under the inuence of a force that varies with position as shown in gure below. How much work is done by the force as the block moves from the origin to x = 8.0 rn'? F (N) | ______|__ | Problem 3 125 pts! Potential Energy A springloaded air gun xed to a table shoots a ball at a target located on the floor. The horizontal distance is D = 2.51) m from the edge of the table, as shown below. When you compress the spring by 1.1 cm, the projectile falls 25 em short of the target. How far should you compress the spring to score a direct hit'? Assume zero friction and air drag. Problem 4125 pts! Work Done by External Forces A (SDkg skier jumps from a ramp with a velocity of 24 nlr's directed 25 above the horizontal. Suppose that as a result of air drag the skier returns to the horizontal ground with a speed of 22 mr's, landing 14 m vertically below the end of the ramp. By how much is the mechanical energy of the skier Earth system reduced because of air drag