When blocking in football, why does a defending lineman often attempt to get his body under that of his opponent and push forward?

Un jugador de beisbol batea un foul recto en el aire.la pelota deja el bate con una rapidez de 120 km/h. en ausencia de resistencia del aire. ? cual sera la rapidez de la pelota cuando la atrape el catcher

Asolid round steel rod 6.25 mm in diameter and 375 mm long is rigidly bonded to the end of solid square brass rod 25 mm on a side and 300 mm long. the geometric axes of the bare are along the same line. an axial tensile force of 5.4 kn is applied at the extreme ends of the assembly. for steel e = 200 gpa and for brass e = 90 gpa. determine the total elongation for the assembly.

The average time that it takes for the car to travel the first 0.25m is s. the average time to travel just between 0.25 m and 0.50 m is s. given the time taken to travel the second 0.25 m section, the velocity would be m/s.