The 445-kg ram of a pile driver is designed to fall 2.21 m from rest and strike the top of a 261-kg pile partially embedded in the ground. The deeper the penetration, the greater is the tendency for the ram to rebound as a result of the impact. Calculate the velocity v of the pile immediately after impact for the following three conditions: (a) initial resistance to penetration is small at the outset, and the ram is observed to move with the pile immediately after impact; (b) resistance to penetration has increased, and the ram is seen to have zero velocity immediately after impact; (c) resistance to penetration is high, and the ram is seen to rebound to a height of 88 mm above the point of impact. Why is it permissible to neglect the impulse of the weight of the ram during impact

Which of the following will increase a population's growth rate? read the following scenario and answer the question(s) below. population growth is at the root of many serious environmental problems. from the ancient babylonians thousands of years ago, to thomas malthus two centuries ago, to present day neo-malthusians, humans seem to possess an awareness of earth's limitations in the face of growing populations. today, our ability to accurately quantify and monitor population growth is very sophisticated. we can measure growth and make predictions about world growth with mathematical and computer models. despite long-lasting, rapid global population growth that is only recently starting to show signs of slowing, we have thus far been able to avoid global catastrophe. can we continue to avoid disaster? which of the following will increase a population's growth rate? increased urbanization increased industrialization increased immigration decreased immigration increased emigratio

Which of the following items would serve as a primary source for a historian studiying the american civil war

Kate is 14 years old and just started taking dance classes with her friends at a local dance studio. this is her first time in a dance program, so everything is new to her. her friends convinced her to join the class since they have been enjoying it for a few months. how could the following terms her succeed in the dance class? ● secondary reinforcement ● identity vs. role confusion ● observational learning how could the following terms hinder her success in the class? ● circadian rhythm ● basal ganglia ● vestibular sense