The vector position of a particle varies in time according to the expression ř = 9.00 î - 8.00t? j whereř is in meters and t is in seconds. (a) Find an expression for the velocity of the particle as a function of time. (Use any variable or symbol stated above as necessary.)

A certain physics problem about projectile motion has several parts, as listed in the questions below. For each, write out what variables (y, vy, ay, t, x, vx, etc) need to be solved for in each part, and at what event or condition, also expressed using symbols and/or known values. For example: “Find ______ (variable) when _______ (variable) equals ________.” How long until the projectile hits the ground? How far has the projectile travelled horizontally, when it hits the ground? What is the projectile’s speed the moment before ithits the ground? What is the projectile’s direction (angle) of flight, just before hitting the ground? How long until the projectile reaches its maximum altitude? What is that maximum altitude? How long until the projectile reaches a wall/building standing 100 m away (horizontally)?

The displacement of a particle is given by s = 3t3 - 42t2 + 109t - 39 where s is in feet and t is in seconds. Plot the displacement, velocity, and acceleration as functions of time for the first 11 seconds of motion. After you have made the plots, answer the questions. Questions: Att = 2.4 ft. v= ft/sec. a = ft/sec? sec, Att= 5.4 i ft, v= i ft/sec, a = i ft/sec? S= sec, Att = 8.5 ft. v= i ft/sec, a = i ft/sec? sec, The velocity is zero when t = i sec and when t = i sec

What is the resultant displacement of a car that travels 2 km north and then turns and travels 4 km east?  Be sure to include magnitude and direction.