A pellet gun fires ten 2.0 g pellets per second with a speed of 500 m/s. The pellets are stopped by a rigid wall. What are (a) the magnitude of the momentum of each pellet, (b) the kinetic energy of each pellet, and (c) the magnitude of the average force on the wall from the stream of pellets? (d) If each pellet is in contact with the wall for 0.60 ms, what is the magnitude of the average force on the wall from each pellet during contact? (e) Why is this average force so different from the average force calculated in (c)?

Introduction to Vectors Part 1 Saadiq Shaik September 2016 1 Cartesian Coordinates in Space A vector is de▯ned as a quantity with both a magnitude and direction. We will be dealing with vectors in three dimensional space, so familiarize yourself with the three dimensional coordinate system. The coordinate planes are the xy-plane, yz-plane, and xz-plane. There are eight octants, but the one we will be dealing with most is the ▯rst octant, which contains positive x, y, and z values. Imagine a point P with the coordinates (a ;b ;c ) and a point Q with 1 1 1 the coordinates 2a2;b3;c ) in three dimensional space. The distance between them is given by the distance formula, q jPQj = (1 ▯ a2) + (1 ▯ b2) + (1 ▯ 2 ) Example 1 p p p Find the distance between the points P = (▯1;0;2 and Q = (1; 2; 3). Solution Simple substitution gives us the answer. q p p p jPQj = (▯1 ▯ 1) + (0 ▯ 2) + (2 3 ▯ 3) p jPQj = 4 + 2 + 3 p jPQj = 9 = 3 1 Likewise, the midpoint of P and Q is given by the midpoint formula, ▯a1+ a 2 b1+ b 2 c1+ c 2▯ M = ; ; 2 2 2 Ex