2. A bullet enters a resistive medium at x = 0 with an initial velocity vo = 900 ft/s and travels 4 inches before coming to velocity 0. Assuming that the velocity of the bullet is defined by the relation v = vo - kx, where v is expressed in ft/sec andx in ft determine a) the initial acceleration of the bullet, b) the time required for the bullet to penetrate a distance of 2 inches into the resistive medium.
c) The graph of velocity vs. position (v-x) and position vs. time (x-t).
This exercise is about statics

Imagine that someone pushes one marble toward a motionless marble. would there still be action-reaction forces involved in the collision? how might the marbles’ motions be changed? ?

What is a neurotransmitter involved in mood reward, addiction, and motor behaviors?

You are a sales representative for a company that makes a new alternate fuel for vehicles. you have prepared a presentation for the environmental engineers to sell your new product. what question do you expect the audience to ask regarding whether the new fuel will cause less damage to the environment? a. do we have to change any parts of the vehicle to use this alternate fuel? b. will the vehicles get better fuel mileage with the alternate fuel? c. how much greenhouse gas does your fuel produce compared with current fuel sources? d. is the alternate fuel more expensive than fossil fuel?