A man is pushing (a) and pulling (b) a sled with a child at the same angle of 40°. The total weight of the sled with the child exerts a mass of 250kgs. While pushing the man is able to move at a speed of 4m/s2 whereas while pulling he moves at a speed of 5m/s2. Calculate total force which is the sum of force along the x-axis and y-axis for the following images (a) pushing and (b) pulling. (Hint Lecture XVI slide 3) (20 points 5% of final grade)

Total solidification times of three casting geometries are to be compared: a sphere, a cylinder, in which the length-to-diameter ration - 1.0, and a cube. volume = 1000 cm^3 for all three shhapes, and the same casting alloy is used. a) determine the solidification times of each geometry b) based on the results of part (a), which geometric element would make the best riser? c) if the mold constant = 3.5 min/cm^2 in chvorinov's rule, compute the total solidification time for each casting.

Me pl give an example of a collision in real life. use the law of conservation of energy to describe the transfer of momentum. be sure and discuss the momentum before and after the collision occurs. you will need at least 3 sentences to thoroughly answer this question.

Suppose that 27 j of work is needed to stretch a spring from its natural length of 6 m to a length of 9 m. (a) how much work is needed to stretch the spring from 12 m to 14 m? j (b) how far beyond its natural length will a force of 78 n keep the spring stretched?