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

a) 4.15m/s

b) 11.22m/s

c) 14.76m/s

Explanation: d).

Sometimes it is possible to neglect an external impulse if it is not in the direction of interest. 

Also, a small force acting over a long time can easily provide more impulse

Please find the attached files for the solution

every society, in order to meet the needs of it's people, has to answer three basic questions:

- what should we produce?

- how should we produce it?

- for whom should we produce it?

this questions must be answered in order to, option b, aid in production decisions.

every country can't produce everything, no matter how rich their land is. it may be a matter of technology, resources or geographical conditions. so, these three questions must be resolved in order to get the most of the production of each land.

hope this !

this is a pretty broad question and can be a pretty lengthy answer. since 1900, women have gained a lot more rights and have become active in the workforce. with women being in the workforce, men play a larger role in family life. many family tasks are shared between men and women, whereas, women used to be the sole family caretakers.

that should get you started at least.